AMD HD2600XT had also an AGP version ...
if not then ATi1950XT
A point to note is that the 1950xt has more dx9.0c grunt than the 2600 but from experience it runs HOT and LOUD.
I have an old machine (son's bedroom) with a Geforce 7900 GS in it that leaves the P4HT3.0 as the bottleneck and is much quieter.
Also, unless you are willing to hunt around dusty shops, you are unlikely to find any of these cards new. Try e-bay but be wary.