Well part of my idea is to have an almost silent system. The least number of fans the better. Right now it would 6 Kaze...which are not exactly whisper quiet.
I've done pass through cooling before where the air wafts from one rad through another and you'd be surprised at how little it effects the overall loop temps. Air can carry a far amount of heat away...it doesn't get saturated in that pass through the first rad. And as long as the KE of the air is lower than the KE on the hot parts of the mobo (gotta love physics) it'll absorb that KE and carry it off...obviously the KE on the air entering the second rad is higher than the air hitting the first rad but it is still lower than the fins of the rad...so it takes more KE with it on the way out...maybe not as much but it still works.
Think of the air like it's a sponge...first wipe is really going to suck up the spill....third or fourth wipe...not so much...but it still does take some of it.
I feel that design is often about compromise to make a happy balance. It's hard to have perfect cooling and a silent PC.
I'm still tweaking the drawings and really appreciate the input guys