You are using an As.s motherboard, so I'd recommend a CM Blade Master for the Megahalems.
5.25 bay. If you have a single DVD player, you have three free 5.25 slots. Unfortunately they are solid, not mesh. Lian Li makes black inserts to fit a 120mm fan into 3 x 5.25 slots. So does Silverstone, and IIRC CM as well. You can put any fan there. My daughter uses a Gentle Typhoon 800 rpm AP-12 there because it is quiet and has enough static pressure to pull air in - but then, the Lian Li thing we have has a thick foam filter. Another choice is an Aerocool 12cm Shark on its 7v line, or a Slip Stream 800rpm. For faster, you can use an AP-13 (1150 rpm) or a SS-1200, or a Nexus Real Silent fan.
If you can get mesh 5.25 covers and there is room above the top 5.25 slot on the inside, you can put a 140mm fan in there. See my sig for a thread on it.
Front lower intake: use your stock fan.
Forward top fan position: flip your stock 200mm and use it as an intake. Move it forward; put some padding at its screw points, and hold it up with 4-inch zipties. Alternately use a TY-140 as an intake. You can either use a PWM Y-cable
, or an Akasa 3-way PWM harness
or a 5-way PWM harness
to hook your Blade Master and your TY-140 to your cpu header.
Why hook your case fan to your cpu header? I do it because I want my fans quiet when the cpu is idling, but I want them full-tilt boogie when it goes on full load. My system is set up so my top intake feeds more air to my cpu heatsink when it needs it.
Remove your unused rear slot covers. That will encourage air to leave from the gpu area.
Rear: I remove my grills and put nothing there, except maybe a finger guard. Air finds its own way out, and you need one less fan that way.
But I can understand your not wishing to mutilate such a pretty case. If I wanted to have a good exhaust, I'd measure my space with a metric ruler. Is there room for a TY-140 there? Remember that a 120mm fan has a circular blade less than 120mm across. If it were a perfect 120mm circle it would cover 78% of a 120x120mm square. A 140mm fan makes much more efficient use of that space. So you can either use the 120mm screw holes of the TY-140, or use double-sticky Velcro to attach it to your rear.
If the TY-140 won't fit, put in another Blade Master, or maybe a 1600 rpm PWM Slip Stream connected to your cpu header (remember - these fans get there power from the psu; they only get their control from the motherboard).
Remember, if you use a sleeve bearing fan, pre-lube it before putting it in service (see my sig, item 3) and re-lube it periodically, as you would your car.Edited by ehume - 10/23/11 at 6:25pm