That Zalman VF900 is not compatible with the GeForce 8 series. If you want VGA cooling, I would suggest the Thermalright HR-03 Plus, if you're after the GTX.
For the price of a GTX, and you get two 9600GTs in SLI. But only if you're going to be playing games on a resolution higher than 1680 x 1050. If not, I would just suggest an 8800GTS 512 (G92). For VGA cooling of the GTS 512, I would recommend the Thermalright HR-03 GT.
For less than those two 7200.10 hard drives, you can get Seagate's newer 7200.11
series. A 750GB only cost around $160. If you're into RAIDing them, I would suggest two 7200.11 500GBs.
Power supply is too much for your system. Any of the following can power that system easily:
Corsair 520HX[N] or
Thermaltake Toughpower 650W[N]
SeaSonic S12 550W[N]
Antec Tru Power Trio 650W[N]
FSP Group FX600-GLN V2.2/EPS12V 600W[N]
Silverstone SST-ST56ZF 560W[N]
PC Power & Cooling Silencer 610W[N]
You really do not need an HDD cooler, because hard drives will actually last longer, when they run a little warm. And the case's cooling should take care of that.
You can get a 2 x 2GB kit of G. Skill for cheaper than those A-DATAs, and they probably overclock better:
Newegg.com - G.SKILL 4GB(2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail
If you want Windows to recognize all of the 4GB of RAM, make sure it is a 64bit version.
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