The good thing about foams are that they pretty much all work. Personally i prefer UFRA and Ellegi, mainly because of price, but wear is also very good ( any gas car based foam is good). Stay in the area of 35-40 shore. i generally run 40f and 40r, with 37f if i want a bit more bite.

Stratus is pretty much the standard in touring car racing, with a few Afla's thrown in.

not sure re gearing a stock although 30-34 depending on the motor