Depends. If you're gonna go quite a bit of multi-tasking, then perhaps an Intel with HT, or even dual core Intel might be better. If not, you'll never notice a difference between the two.
Not so good barebones kit, you'll definatly want socket 939 if you go AMD, as Socket A is dying. The CPU fan will be really noisy at 4500 rpm, 500 watt PSU is plain overkill, 512 MB pc2700 is too little too slow as you'll want 1 gig of pc3200.
If you're not planning to do any gaming on that machine, then you may as well get a motherboard with on-board video and use that. Saves money