A.G.P. or P.C.I. for Asus KL97-XV

Hi,
Am looking at purchaseing a new graphics card for my old computer, I was wondering which of the above is most suitable as my machine is 5yr. old,
however if at all possible I would like to get a A.G.P. AS I amconsidering upgrading in the next couple of yrs. & would like to use the card I purchase if at all possible. My machine is a H.P. 8210 P2 w/- said motherboard & a A.T.I. Graphics Pro Turbo [atim64=vt]. which I wish to replace.
Thanks Heaps
Norm