I would recommend spending a little more on the mobo as well... I've noticed you've opted for the AX8, which uses a Via chipset. Yet on overclockers.co.uk the AN8, which uses the std nForce4 chipset is the same price! I've used Epox/Via combination for a few years now & my next system (shortly) will use nForce. I've read countless reviews which say quite simply nVidia is better, specificially for us gamers. Also, if you can afford it, spend a few extra £'s and get the nForce Ultra board.
Agreeing with the others, the main joy of 64-bit is the amount of memory that can be allocated by the system - totally smashing the 4Gb limit. However, you won't really notice performance increases until you have over 2Gb memory. I would highly recommend getting 1x 1Gb DDR400 (Corsair do a 2-3-3-6 XMS module now) - then adding another one in the future. Then you will have the benefits of Dual-Channel and a lightning fast Windows x64 system!
My current system is knackered (over-worked and under-paid)... so as a stop-gap, I'll be replacing my dying motherboard - but sticking to Socket-A / AGP. My videocard (stock Leadtek FX5900 128Mb AGP) is being ditched for a AGP 6600GT 256Mb GDDR3. Although, my current card is quite high-end for the 5xxx series, the over-zealous cooling effort (bless Leadtek) is too noisy!
Although the raw performance between the cards isn't much, the 6600GT is a good choice... fairly cheap, Shader Model 3.0 (& other next-gen techies), cooler and quieter. Plus, get the faster GDDR3 memory!
Apologies if this has made you all fall asleep... anyway...
Abit AN8 nForce4 Ultra
(2x512Mb) or (1x1Gb) CL2 DDR400
GeForce 6600 128 GDDR3 (or ATi X800GT)
Hope this help!
