Wheel questions?

I want to know whats the best rim/width combo to run out back? Can I fit a 315 or 305 out back? ? I dont mind have to bang out the fender a little bit...These will be strictly for weekend/track driven and I will have drag radials on for during the week. Also does anybody know who makes these at the best price? I dont even know who makes the rims they came with the car

