I planning to watercool my main rig shortly, mainly because summer is coming and I've been mining for Litecoin for a while now. The main snag is that the FT03 doesn't have much room for radiators so I'm planning an external radiator setup like this guy over at OCN, except I'll be using a single loop and narrow 13/10mm tubing instead of 19/13mm for space reasons. Here are the components I've chosen: XSPC RayStorm (as recommended by CPC) Aquacomputer Aquagratix 7970 (ditto) Phobya Xtreme 200 Silverstone AP181 Phobya DC-260 + Res combo Primochill PrimoFlex Pro 13/10mm tubing Alphacool 13/10mm fittings (will also use 45/90 degree fittings as needed) Phobya Quick Coupling Bulkhead 13/10mm (for the external connection to the radiator via a PCI slot) Are all of those components I've selected going to be fine for this build? In particular, is there enough cooling capacity for the CPU/GPU and does the Air Penetrator fan give enough static pressure for the radiator?
What voltage you running your overclock at? Have you clocked your 7970 also? In terms of radiator surface area, a 200 rad sits mid way between a 240 rad and a 360, so I think you'll be okay in that respect. There can be a lot to consider such as flow rates, fin density, static pressure etc. With all that, there can be a tendency to over think it. Just keep it simple and you'll be alright.
CPU is currently at 1.3V, not pushed it harder yet so I'm sure there's plenty more headroom left. 7970 has been pushed to 1175Mhz without overvolting so there's an opportunity too. For me it's more about keeping the system quiet and cool rather than absolute performance.