...glad I could help a little bit...re rep's - until recently, I did not really know what they were and asked myself why folks had so much of their equipment 'repossessed' , or may be lost out in the computer version of 'pink slips'
First, to define some parameters, my understanding is that your are really talking about two machines, with the new (second one) running "only" one 670, while the first one is getting a GPU and cooling upgradeOn the mobo
I would whole-hardheartedly recommend the Asus ROG Max Gene...it's OC abilities are very strong; its limitations vs Formula and Extreme have more to do with the number of expansion slots (apart from Thunderbolt; Wi-Fi and built-in eSata SSD)...and a Gene can run SLI / CF with no problems at all.
The Max V E has the MOST slots and for my own purposes that comes in handy (tri-SLI now; co-processor, 10 GIG multi-NIC cards and SAS RAID for a later work environment function). Re OC capability then, the Max V has a bit higher headroom - but we're talking past 6.7 Ghz at LN2 etc .
The other item is what I had mentioned before - the OC Key - it's the software on the screen in this video http://www.youtube.com/watch?v=80gmbFwG4Aw
(see around 3:40m mark for extra amusement).
Even for OC attempts at 5 Ghz and a bit beyond, the Max Gene is a very strong solution if you don't need the extra slots and OC Key. A friend of mine just finished a build of a Max Gene last week, with a AX1200, 2x 7970s and water-cooling (Thermaltake 2 Ex / 240 rad), ALL IN ONE OF THOSE smaller CoolerMaster HAF cube cases...he needs s.th. this powerful, reliable but also compact as it holds his company's proprietary software re 4K video compression when he travels with it to big US cities for demos with clients...the last thing he wants then is a mobo that isn't top notch. Then there is also the Hardware Editor's 'Gold' award here: http://www.hardocp.com/article/2012/06/28/asus_maximus_v_gene_microatx_motherboard_review/7#.UR7e12cmr1J
...so mobo is a no-brainer - Max Gene...for your purposes, really the best option (unless you need more slots or want to OC with LN2...)PSU
For the dual GPU one, AX 1200/i , or OCZ 1050 gold (I prefer the AX1200)
For the single GPU, your original choice would be fine - but make sure that you don't really want to stuff more video cards in the thing later and then realize that your PSU can't really handle it.
...I am going to get some critiques for this, but I would say that at the bare minimum, assume 220w for your CPU oc 3770K at 5 Ghz, about 400w for your SLI / CF GPUs (single stock 670 = 144 with +22% option; single 680 = 175 + extra w option)...THEN add another 200 watts on top - that should be your PSU (single rail, with as high an efficiency rating as the budget allows).Cooling
The PSU summary nicely 'segways' into the cooling discussion -which I think is your biggest remaining questions set.
Please have a quick look at this graph (source: Sin0822 / Ivy Bridge Overclocking guide)
Once you get past 5.0 GHz at 1.5v with any kind of decent load, you're looking at 200 watts...at 5.4 with 1.6v its a lot more than that ! So keep that number in your mind as the first 'load factor' for the H220
Now add 'roughly' 350-400 watts for SLI GPUs, depending on their OC state...
My first point would be that I really like the H220, up to its appearance, the Thermaltake 2 Ex was my unit of choice re closed loop...the H220 has the HUGE advantage that apart from some stronger pump components it can be 'modded'
with extra cooling arrangements for GPUs etc - in essence, it is a hybrid
between a closed-loop and custom-loop (very smart market positioning by Swiftech, btw). You can also 'mod' a Thermaltake 220 or Corsair H100 - but only with a pair of sizzers
My second point would be that NO MATTER WHAT, a 'stock rad' H220 asked to just cool an OC'ed 5 GHz 3770K (approx 200 watts) will do better temp-wise than one which also carries AN EXTRA 350-400 watts GPU heat (never mind Max Formula VRM wc).
This is not to say, that a H220 cannot handle that; what I was suggesting is the following:
Get the H220 and initially set up your approx 5 Ghz CPU as the only item on it...run it for a few days with reasonable benching / stress testing noting ambient temps as well as system temps....that's your base line right there.
Then add the GPU coolers (more on those below), with an extra 240 rad - run some more reasonable bench / stress tests for a few days noting all the above variables and see how that performs differently.
The kicker is that you probably can add another 120 if not 240 rad, but adding more rads and also two GPUs may obviously make the pump - solid as that one is - work harder...and if you are using the Max Formula board, I believe that it has water-cooling barbs already set up for the VRM, so you would want to throw that one into the loop as well.
What I have seen done before is:
a.) a split of the system into two custom loops (when CPU lowEST temps are critical) or
b.) a 'helper' pump installed into the single loop - in your case the H220.
It should be possible, but I do not know for sure - the best folks to answer that one are the Swiftech reps...just ask them what would happen of you extend the H220 loop to not only cover VRM and two GPUs with a total either two or even three rads, but also throw in one of their free-standing pumps as a 'helper' pump, or as 'extra insurance' (pumps like that are between $60 -$90). It all goes back to whether you ask the H220 to deal with 200+ watts, or 600+ watts of generated heat.
As a somewhat separate but related item, here is a quote from some folks at YouTube who were noting how OCing had changed their cooling requirements: " With the 3770k at stock speeds under full load the H80i will keep the cpu around 60c to 65c,if I overclock it to 4.2ghz the H80i keeps the cpu around mid 80c,I also had the? cpu at 4.6ghz but had to go back to 4.2ghz because at 4.6ghz even with the H80i running at max speed the cpu would get up to 95c.
These ivy bridges are actually hotter than the 6 core Core i7 3930K my other pc with the Core i7 3930K clocked at 4.6ghz doesn't even go over 80c under full load."
A final point on GPU coolers
I mentioned that I'm working on a custom solution which consists of taking generic GPU blocks and add a custom-fab VRM block in a way that can also be transferred to Titans later. However, if I would keep the SLI 670 (instead of Tr-SLI which forces me to deal with the heat in a different way), I would go for full blocks.
As such, I stared asking around to see what actual owners of dual 670 water-cooled blocks were saying... the guys tell me there are only two or three choices ('EK' http://www.youtube.com/watch?v=TbKDjjY6Wq8
, Heatkiller / watercool.de or YoutTube here: http://www.youtube.com/watch?v=KKz9QflIwoM
I know one person who has had experience with both and he prefers the 'heatkiller', but it seems to be a question of visual design and metal 'quality' for him, rather than a performance question (temp-wise, he said that there were within 2 or 3 degrees of each other).
While you can order direct from those folks, in the USA, FrozenCPU.com would be your best bet for these specialty items...just make sure you know whether your 670ies have what is called a 'reference board design' or a 'custom board' design such as the Asus DirectC-Cuii
Good luck with your new build