I would keep everything as it is. RAM and 3000+s are super cheap that if he downgraded to what Tyr said, there wouldn't be a significant change in cost. It would turn out to be $100 difference at most, which I don't think is worth it.
Yes, make sure to include WinXP.
Personally, I wouldn't worry about AS5. 3000+ Venices run quite cool with stock paste anyways.