There's been some difficulties with ATI's Radeon series, so unless you're going for the FireGL, I'd reccomend getting a GeForce rather than a Radeon, which should run fine as far as I've heard...

If you're looking to make some high poly stuff at some point however, you should probably invest your money in some more RAM if the errors you're getting now aren't so bad that they get in the way of using Maya...