sorry - another heat exchanger question

[pgm27]

I know this has been addressed, and I've searched threads, but I am still confused. I have a 1986 3.2 with stock heat exchangers, cat bypass, and FVD muffler. I'd like a little better throttle response, and more sound without it being obnoxious. I've read varying opinions about backdating heat exchangers in a 3.2 motor, and whether it helps or not.

should I consider switching to SSI type exchangers, and a different muffler? Or should I just consider going with a sportier muffler and SW chip? Any muffler suggestions if I do retain the stock heat exchangers? I guess that to summarize this question, what are people's opinion about best exhaust set up for this car for both better sound and throttle response?

I am very non-mechanical, and any work will be done by a mechanic.
thanks, Peter