Hi Digitell,
I'd love to be able to afford such a machine as svdl wants.
However, there is still a lot of hardware without 64-bit drivers, which may never have 64-bit drivers [ especially with Vista available now ].
So, unless you are willing to buy 3+GB of memory, and want Microsoft OS,
staying with WinXP standard (ie. 32-bit) or going to Vista will be better in the long run.

I suggest that you have a look at what PC magazines are available where you live.
Look up there web sites to see if they have hardware reviews.
PC World  Magazine at www.pcworld.com/reviews/hardware does - it has a "top 10" for both Power PCs and Value PCs.
The technical specs and brands of these can give you some indications of which brands
and models of PC , motherboard, graphics cards are best for your budget.
Logging on to www.dell.com and doing a "custom build" of a PC can be a handy comparison too, both price-wise and specs-wise.