Do you really need the combo board? Bearing in mind that there are only 2 DDR3 slots.
From what I can see there you're wanting to change the cooler on the 8800GTX. The EVGA 8800GTX cards offer 10 years warranty which won't be void when changing the cooler.
Personally I'd go for the 620w version of that PSU, especially if you're planning to add more hard drives/accessories. A 520w will handle all that perfectly, but I'd just got for 620 to be 100% safe.
Also, don't forget a nice backup solution (another 500GB maybe) if you haven't got one already.
Craig.