about to purchase

I was about to buy a computer from unitedmicro.com but i just wanted to run 2 setups by you guys, cause you're all pros, and i've been out of the computer scene since teh radeon 8500 was top of the line (long time)

feel free to completely criticize my choices, becuase i know nothing about motherboards or nvidia video cards (just that they're "better" than ati, which is why i finally sided with them) I think i made 2 decent setups one with pentium D (which i assumed was after P4), and athlon 64 x2... i don't think the vid-card selection from unitedmicro is excellent so i'd be willing to get 2 videocards from somewhere else if someone could suggest other SLi ones...

thanks in advance:

AMD system

Processor:
AMD Athlon 64 X2 AM2 3800+ DUAL CORE RETAIL BOX with HEAT SINK & COOLING FAN

Cooling Fans:
Thermaltake A1770 VENUS 7+ Heat Sink & Cooling Fan AMD
Recommended for Athlon 64 and Opteron

Motherboards:
Asus M2N32-SLI DELUXE AM2 nVIDIA nFORCE 590 SLI Chipset DDR2 533/667/800 SATA GBt Lan Audio ATX

Memory:
(2) 1GB DDR2 667MHz (will probably increase later)

Hard Drives:
(2) Western Digital 250GB 7200 RPM 8MB SATA-II WD2500JS

Floppy Drives:
1,44 3.5 Floppy INT Black

Cases:
X-GEAR Black 420wt w/ USB Ports Side Panel W/UV Blue LED Fan ATX

Power Supply:
Aluminum Power Supply 680wt UV Blue Fan,Blue Led Light Blue SATA PCIe SLI, Cross-Fire ready (it recommended to upgrade supply if using SLi don't know if it's necessary or not)

DVD ROMs:
LG 16x DVD ROM IDE INT Black

DVD-RW:
LITEON 16X DVD+RW/-RW DUAL LAYER IDE INTERNAL BLACK

Video Cards:
(2) eVGA 256MB GeForce 7600GT PCI-E SLI Ready N554
total price: $1319

Intel system:

everything's the same except

Processor:
Intel Pentium D Processor 940 with Dual-Core 3.2GHz 2x2MB 800FSB LGA775 -Box

Cooling Fans:
Heat Sink & Cooling Fan for INTEL P4 LGA775

Motherboards:
Asus P5N32-SLI DELUXE LGA775 nFORCE4 SLI DDR2- 667/ 533 2PCI-E x16 SATA Gigabit Lan Audio ATX

price:$1350

so what do you guys think? are these good, or are they completely wrong in their customization?

supposed to be mainly a gaming computer