You might check with Wheel Vintiques or perhaps Mooneyes. I beleive they can set you up with a 15"-17" rim with the clips to be able to use the stock caps. I would suggest either the 15 or 16, whcih would be more compatible with the factory available trim ring sizes.
A taller tire wouldn't be a good option in this case, as with the Camaro subframe, the ride hight is most likely lower than stock. Probably something along the line of a 28" tire would be good, such as a 235/75/15 or 245/65/16.
