I'd defiantly recommend AMD, faster performance and much cheaper than Intel CPUs. My god, just the word 'Pentium' adds an extra 100 bucks or 2 :eh:. But do stay away from the really cheap AMD CPU's.

Nvidia video would be the way to go, once again, usually cheaper and (in most cases) better performance than ATI. You really do get what you pay for, so stay in the higher end region, and just ignore all the bells and whistles they try and force onto the card :mrgreen:.
AGP vs PCI doesn't really matter, though most appear to be heading the way of PCI.

Most motherboards are pretty much the same, just get one that matches the CPU, and will support the video.

You really don't have to spend an enormous amount on a PC these days, and cheaper brands can easily match the performance of leading names.

but that's just my 200ths of a dollar :mrgreen:.