Slicks

You don't need a gigantic slick to hook that car. I'd go 15" wheel because there are more tire options. Assuming its an auto, you're going to need more gear and/or a converter to see any benefit.

26*8.5 or so should be fine and fit with no issues with the correct backspace wheel.

Remember, if you have a slick, you have to have a driveshaft loop.

IF you go with a DOT type tire (ET Street/ Quick time Pro, etc) its important to look at the actual measurements because the sidewall will state a larger size than the tire is. One benefit to running a DOT slick is that the rules are looser regarding loops and the like (but can vary from track to track).

I like to run shorter slick/less gear if possible, so I can run a taller tire on the street to make the gear more liveable.