buy 32 bit or 64 bit

[wheeze]

If you're buying new hardware, 64-bit is surely the way to go. New RAM is cheap these days (try finding DDR RAM for an old motherboard) and I'd load up with as much as you can afford. With 64-bit you can easily take advantage of it along with the larger register sizes and data paths.

This is like the switch from 16-bit to 32-bit when Win 95 first came out.

[Paqman]

Pretty much all x86 CPUs are 64-bit anyway, and have been for a while. You'd have to go out of your way to even find a 32-bit one. So it's not really a decision you have to make.