1000 Build, Need help with compatibility and longevity

So I've put together a gaming build based on a few of the threads from the past 2 days. I need help with how compatible the parts I've listed are, if there are any problems with them, or any suggestions you may have to increase performance.

I appreciate any input you guys have

APPROXIMATE PURCHASE DATE: Will be purchasing tomorrow

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming, I'm really looking for longevity here as well. I would like good performance machine that can be upgraded easily in the future and last me a long time.

PARTS NOT REQUIRED: keyboard, mouse, monitor, speakers, OS

PREFERRED WEBSITE(S) FOR PARTS: I prefer newegg

PARTS PREFERENCES: no preference, I basically want the best performance for 1000$

OVERCLOCKING: Yes

CROSSFIRE: Yes, but later.

MONITOR RESOLUTION: 1680x1050

ADDITIONAL COMMENTS: Here is the list I came up with so far

http://www.newegg.com/Product/Prod [...] 6811129042 $59.95
Antec Three Hundred Black Steel ATX Mid Tower Computer Case – Retail

http://www.newegg.com/Product/Prod [...] 6822136319 $69.99
Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM

http://www.newegg.com/Product/Prod [...] 6814161276 $189.99
HIS H489F1GP Radeon HD 4890 1GB 256-bit PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

http://www.newegg.com/Product/Prod [...] 6817139006 $119.99
CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Retail

http://www.newegg.com/Product/Prod [...] 6820227297 $75.99
OCZ Platinum 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model OCZ3P16004GK - Retail

http://www.newegg.com/Product/Prod [...] 6835233029 $39.98
XIGMATEK Dark Knight-S1283V 120mm Long Life Bearing CPU Cooler - Retail

http://www.newegg.com/Product/Comb [...] mbo.203158 $354.99
ASUS M4A78T-E AM3 AMD 790GX HDMI ATX AMD Motherboard - Retail
AMD Phenom II X4 955 Black Edition Deneb 3.2GHz Socket AM3 125W Quad-Core Processor Model HDZ955FBGIBOX - Retail

$910.88 + $10.06 Shipping

Thanks

^Nice setup...
The CASE and the HDD are available as combo with $10 discount...
http://www.newegg.com/Product/Comb [...] mbo.204205

And that HIS card' price have jumped to $240

Gigabyte card... - $10 more but with same $20 Mail-In-Rebates and Free Shipping + 3 years warranty...
http://www.newegg.com/Product/Prod [...] 6814125276