what suggestion do you actually want? if some of the components you choose are bad or so?
it's a good choice, and it depends on your cash flow of course
(say e.g. getting an 8800 with 640 mb instead)
the only comment about the psu is, do you know the noise level? the data sheet doesn't give any db numbers, or?
i just bought a tagan 600W dual, has 19db background noise, under full load ca 27-29db.
regarding watercooling i would suggest to google and search some of the overclocker sites.