The Abit Kt7 is a good MB, though you should get the Kt7A now. This will allow you to use processors above 1300 Mhz (100 Mhz ddr fsb) in the future.
You may also consider going to a DDR Ram board at this point. I would recommend the Asus A7M266 for that. (Note: The A7A266 is not the same, totally different MB.)
There are many things that impact framerate, but you will definately get very good framerates with that setup. (Given you have plenty of ram, etc.)