Man I was in your shoes, just about made myself sick trying to make this decision. I ended up going with Borla Pro XS using 3" with a x-pipe then into 2.5" tail pipes. I liked it so much I did the same thing to my 57 and my brother did it to his 67 Camaro.
I was looking for the crisp tink/tink sound at idle with my 383 stroker and searched the internet and youtube for a few months before deciding on something..This shop here Kenny's Muffler has some excellent youtube videos of mufflers done on cars with great sound and you can also seach youtube for the car and mufflers, there is always something for everyone there..