I've had a go at mapping out the system,
I forgot to label the large grey block under the res, its the DVD drive. Also the upper pump is only displayed in that position for illustrations sake, it would be side by side with the bottom pump.
The space in the PSU/dual80 rad compartment isn't useable either, as I'm going to put a second smaller SFX PSU (320w) in there to power the 6800's + pumps + fans. (The Antec will power the board + drives)
Now with the fans+dual120 rad mounted at the front 5.25" bays, it leaves a space behind (on top of the dvd) that is 140mm width x 100mm depth x 280mm height.
As I mentioned before I'm now looking at the MCP350 (DDC) over the MCP650 for a couple of reasons; a) the size, its a lot smaller, b) the flow drop off when you start adding blocks is quite low, while the 650 suffers quite a bit.
Now this 140x100x280 space needs to contain the res and pumps.
One option is to make a res box out of perspex/plexiglass; now I see this as more trouble than its worth, I doubt I have the skill to do a good job of it (ie no leaks/designing it in such a way that it won't crack). If I could find someone who can do this for me I'd more than happy to generously compensate them
(hint
) It would supply both loops, and due to its dimensions should be able to hold 2litres +.
Otherwise I could buy two seperate res' for each loop. Looking at
Trodas' thread he's made some excellent tank-o-matic style ones.
Now if I went for that kind of design (couldn't be 250mm like his reference design, 200mm tall max, to allow space at the bottom for tubing/barbs) each loop would have its own res, and it would look a 100 times better than a big res box, but wouldn't be able to hold much - 200ml's per res
Would I see a big difference in the way the WC system works if I had a res with 2litres or res' that can hold 200ml each? (400 total).
Trodas' style res would be better for the dual 120's air flow; with a large box res the cool air being blown through the rad would hit a wall once it got to the res. With the tube like res' this wouldn't be such a big issue as there would be space between them.