new build

What will you be using this computer for ? You could save enough buying an i5 system to get a good SSD for your boot drive. The i7 would not be any better for gaming and not really with apps unless you need the HT or are a hardcore multitasker, that is why I ask. Also with the SSD, the i5 system would probably be faster then the i7 and the HDDs, especially for OS related performance.

Edit: you could also tell us what your budget is, that would help when picking out components.

Since you did not specify much direction, this is what I would buy for myself. An i7 setup would be 200-300 more. Don't forget about price matching, as you will save about another 50 bucks off those sale prices. If you do not game much, keep your old card otherwise get this new one and you will be a happy camper. If it is too much you could opt for the 5850 instead.


Video card This will make that 9800gtx cry
Memory
MB
SSD there are a bit better and larger capacity ones out there, but this is still the best bang for the buck. Remember you only need the SSD for your boot drive. Games storage can go on other HDDs.

CPU Most of these can overclock to 4 GHz

CPU HSF remember high static pressure is better than high CFM for CPU fans when buying one. You could keep that AIO water cooling thing, but they are not as good as a real water set up plus your case has good airflow. If you are not overclocking just use the stock cooler, it will be fine.

Edit: Your PSU will be fine for these components.