If you're going to go down to a 2.25" duals (which you will on the convertible if you don't want to space anything) you want mandrel bent pipes. Anything less is sacrificing hp for the 400.

I've yet to find anyone in my area that does mandrel bent custom exhausts. Most use compression bends. Either that or they have to cut and weld prebent sections which can't be cheap either.

Summit does sell a mandrel bent aluminized 2.25" exhaust. Does it fit a convertible? Don't know.