My first custom built pc...specs

[P4ULY]

I’m putting together my first custom built PC at the moment. I think I have found a set up that does everything I require, which is basically playing games & CAD work. I have been reading as many reviews as poss so that I can get the best for my money (£1000). I just wanted your opinion on everything below, would you def change anything?

CPU - Intel Core 2 Quad Pro Q6600)

Memory - OCZ 4GB (2x2GB) PC2-6400C5 800MHz SLI-Ready DDR2

GPU - Leadtek GeForce 8800 GTS 512MB GDDR3

PSU - Thermaltake ToughPower 750W Modular Power Supply

Motherboard - Asus P5E Motherboard

Wireless Adaptor - Netgear WN121T 270Mbps RangeMax NEXT Wireless USB 2.0 Network Adapter

Bootable Drives – 2 x Western Digital Raptor 150GB Drives in Raid 0

Storage Drive – Western Digital 500GB Caviar

Optical Drives – 1 x LG GGW-H20L Blu-Ray Rewriter & HD-DVD ROM & 1 x DVD Rom (From old PC)

Operating system – Vista 32

Case - Thermaltake VD4000BWS LCS Kandalf Full Tower

 

[P4ULY]

I can't make my mind up about 32 or 64, how difficult would it be to get drivers under 64 for the above hardware? I really want to go 64, but don't want to cause myself untold grief as I'm quite new to all this.