didn't read through all the comments here, but in general: If you got that low priced Voodoo2, perfect.
Also, many voodoos, though expensive, may still be the best value in the PCI segment.
Many others around, but none of them packed to much punch, compatibility or image quality.
Still not all too rare, in my not-so-up-to-date experience:
-ATI 3d rage
-Maybe earlier nvidia like Riva 128, if you find a PCI one
If not period correct, there are much more recent PCI cards like Nvidia up to Geforce 6 (or even 7, I've heard) - depends on the driver issues and what you want to play with those.
But, apart from ISA sound for DOS, this may just be the mother of all rabbit holes.
It gets much easier and more affordable once you hit AGP territory, but none less complicated...