What to do
 

Ok heres the thing I own a 93 Civic H/B and a Del Sol. They both have rice cans on them and i just can't stand the noise anymore. The Civic has 2 1/4 piping and the Del Sol has 2.5 piping. I was thinking of putting either a ITR, GSR, SIR muffler on them. Will these mufflers fit on both cars? Would i have to put a resenator on it. What would you do? Any advise is greatly appreciated.
Thanks