Windows 7 will turn that system into a snail if you try installing it. So I vote for XP!
Well its upto his preference. IMO, 32-bit fulfills all my computing necessities so I don't feel any need for 64-bit.
So I guess, you should go with 32-bit. Also I had an 8400 card earlier - So its better that you go with 32.
All times are (GMT -06:00) Central Time (US & Canada). Current time is 5:50:38 AM