First off, I'll admit my knowledge on video cards is limited to what I've googled in the last few hours (though you'd be surprised how much you can quickly learn).
Our group will be running large simulations through one of the high-end graphics cards later on in the year. I'll be in charge of getting this up and running, but in the meantime in order to learn CUDA and other GPU aspects I need some low cost card for my own machine. But I couldn't find any post that would exactly answer my question.
I'm running Linux on a Dell Optiplex 760 (small form factor)