Check this out....

http://web.njit.edu/~cas1383/proj/main/

It may help a little....

definately stick to fiberglass cloth instead of mat, I'm still finding pieces of fiberglass here and there a year after I finished...

If you're doing a fairly large job (sub box size) retrofitting you may want to buy in bulk... some stores will cut you custom legnths of fiberglass instead of buying it in packages (it's a hell of a lot cheaper), same deal with resin, you may be better off buying a gallon instead of quarts, provided you're going to be using it all....