Graphics Card Problem

I am a fresher to OpenGL area. I intend to do a course in Graphics, which will include OpenGL. The current card on my m/c is Sis6326, which doesn’t support OpenGL (GlutSetup didn’t run).
Hence I intend to buy new graphics card. Other requirement is that, the card should also be supported by standard Linux distributions. The sis card fails in both!
So can u please suggest me a card? From the preliminary research on this site, I have narrowed my options to voodoo or Riva TNT. Please guide me in this.
Most important thing is, how do I know the card supports OpenGL and linux complient, before buying? And also the card availability in India, if possible.
Please mail me ASAP.

Between the two you listed is it easy. Take the TNT.
NVidia has people working on linux drivers so all cards from the TNT and up works. If you have the money is a GF2 MX even better.