It depends on which mufflers are being put on. Here, its $300-$350 for exhaust with Flowmaster mufflers, which I think are about $65 ea anyway with chrome tips. I may sound high for 20 ft of pipe, but take into consideration, the guy has more that $300 in equipment, shop, etc and knowledge to do the job. That should be worth more than 20 ft of pipe. Congrats on th 96, I really like that body style, and glad to have ya back, squarebody or not.
I like the cat back because it acts kinda like a y pipe. A series 40 flowmaster for deep rumble, series 50 for a little quiter, or a single chamber for a loud rumble. A friend has the single with 2=1/2" pipe and it sounds awesome.. Go one it and the two out for your muffler, then dual out from there. Unless your gonna do a massive amount of mods to the engine, you'll never restrict it bad enough to need dual.