I agree make the track home for nitro sedans and 8th. There is a Track Maker program on the net somewhere that can help you start off with some designs. Do a search online for some track layouts. 200x100 is a great size to start with. Make accommodation for pit lane, pit area, and drivers stand. A ramp would be great for any racer who happens to be in wheel chair.
Trying to live every day like its the last....