I don't think you'll have a problem as long as you have a way to make a connection from your graphics card to your TV.
I have never used ATI cards for MAME systems (not a preference, just happened to have access to a few GEForce 5200 cards with an S-video output). I like them. Some here have said ATI cards work better for TVs in terms of quality. FOr what it's worth, my TV connection worked thru the graphics card even without installing the driver. One thing to watch...make sure you disable your on-board graphics within your BIOS. If your computer doesn't have a graphics card, you're probably working off your motherboard.