You can have fun going sideways...in the rain.
A supercharged 2.0 NC MX-5 is a very good proposition. Cosworth made a SC kit.
On the "no smile" versione the suspensions need a bit of work. A Bilstein PSS kit is enough. You can get a used one, put the engine kit and the suspension on and you have loads of fun for very few money.
http://www.good-win-racing.com/Mazda...1-0214BME.html