Thanks! I was thinking about the Rasa 240 originally and yes I suppose I can do without the secondary optical (as though I was using it anyways lol).
I have the spot in the back of the Antec 1200 where there are two case fans vertically installed already, so I'll just mount the 240 rad where those were. Could I keep the Antec Tricool fans on the rad? Or should I use the fans that come with it? I've read reviews saying that the fans make very little difference and others that say that they are important.
Arksniper: Could you explain what the silver kill coil or pt nuke is? I assume it kills bacteria (lol) but does it go in the res?
You could use whichever fans are appropriate for whichever watercooling kit (or just radiator) you end up going with. With high FPI density radiators (HW labs Black Ice line) you want high RPM fans (>1200 rpm), and with low FPI density radiators (Swiftech QP line, XSPC RS series, etc) you can use lower RPM fans and still get effective cooling.
fr0st just posted a great quick guide on some of that stuff here and I've added links to it as well.
Fans make or break a radiator, so they are more important than people lead on about.
You could certainly mount a 240 rad on the back of your case. Is there other ventilation in that case? Corsair recommends sucking air in from the back and through the radiator, dumping the heat into the case with their H50/60/70 kits. That's great for keeping temps lower, but it increases internal computer case temperature. You have to see whether your case has adequate ventilation to make that work. If not, then you can always have it exhaust out of the back of the case, you'll just have to probably use the fans in a pulling configuration to be able to mount the radiator on the back of the case. Really it's only a minor impact on cooling temperatures.
For the kill coil, you just put it in your reservoir so its in contact with the water. PT nuke is a liquid drop that you put a few drops (follow instructions, I'm WAY overgeneralizing) into anywhere in your water loop, and it'll prevent bacterial or algal growth in your loop.