yep but obviously restricted to AGP
Ahhh, me and my quick answers

Well I think both cards will get held back by the 2400 so the better card is the better option for long term. Short term then I'd save my money and upgrade my whole system.
I remember years ago when I had my 9800Pro in my 2400XP system and it scored about 11,000 in 3dmark2001. When I moved up to the 3700+ skt939 and decent DDR I got my 9800Pro to about 21,000. So I even think his current card is probably being bottlenecked ever so slightly by that CPU (might).