Going to build a mid-range C2D e6400 system...help me out!!

I'm looking to build a nice medium-low to mid-range gaming rig that will last me until DX10 is necessary to play games. I mostly play RPGs ala WoW/FFXI and I'm looking to play Age of Conan and maybe Warhammer when they come out later this year.

Gonna be using the computer mainly for just standard stuff (web browsing, watching videos, playing games, photoshop) and probably not extensive video editing. If I overclock it's going to be modest.

This is going to be my first build without somebody holding my hand while physically putting it together (and that was 3 years ago) so I'd prefer an easy to configure setup. I'd also prefer to use the junk case and PSU I got free after rebate if possible. Sorry for all the words...

Have already: DVD/CD burner, generic floppy drive, junk PSU and case listed below, mouse, keyboard, 19" flat panel monitor (both DVI and VGA)

Want to use:
CPU: Intel Core 2 Duo E6400 Conroe 2.13GHz 2M shared L2 Cache LGA 775 Processor - Retail
http://www.newegg.com/Product/Prod [...] 6819115004

Case: Ultra Wizard Blue Mid Tower Case (Steel)
http://www.ultraproducts.com/produ [...] ductID=251

PSU: Ultra V Series 500W PSU (28A on +12V…bad reputation but I‘d like to use it if possible)
http://www.ultraproducts.com/PDFs/ [...] 1841_1.pdf

VGA: BFG Tech BFGR76256GTOCE GeForce 7600GT 256MB 128-bit GDDR3 PCI Express x16 Video Card - Retail
http://www.newegg.com/Product/Prod [...] 6814143049

Hard Drives: Seagate Barracuda 7200.10 ST3320620AS (Perpendicular Recording Technology) 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive - OEM (I'd like to set up a RAID 0 with these drives)
http://www.newegg.com/Product/Prod [...] 6822148140

Unsure about:
Mobo: GIGABYTE GA-965P-DS3 Socket T (LGA 775) Intel P965 Express ATX Intel Motherboard - Retail (I've read in a couple different places that this board is very nice as long as you get a Rev. 2)
http://www.newegg.com/Product/Prod [...] 6813128012

Memory: A-DATA 1GB (2 x 512MB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory - Retail (I picked this because it has good reviews and is rated at 1.8v so I hopefully don't have to troubleshoot to get it to work with the board)
http://www.newegg.com/Product/Prod [...] 6820211064

CPU = $224
Motherboard = $135
Hard drives = $190
VGA: $144 ($79AR)
Memory: $116
Case: freeish
PSU: freeish
Total: $809 + whatever XP pro ends up costing me (trying to get it through my school)

Final question: Do you think I should spring for 2048MB RAM right away? I may upgrade to Vista but not until most of the kinks are worked out. Thanks for your help...