Is there any good aftermarket exhaust to get? Good sounding, not too loud, not too rednecky, etc...

 

There is an aftermarket variant of every component of a Cherokee's exhaust. From header to downpipe, cat and cat back.

Just go on Quadratec and check out the options. So many.

Also - please please please keep a catalytic converter.

 

I installed a magnaflow cat back and noticed my catalytic was also shot so i installed also a down pipe and a magnaflow cat converter. Very happy so far, not loud and exactly what i needed. Catback was around $600.00 and cat converter don't remember.
Check youtube for a video from Trail recon about their cherokee mods and the exhaust.

 

I installed a Banks Power Monster Exhaust system on my 2000XJ. Banks has real test data to back up their performance claims. The system is not very loud IMHO. I've been very pleased with it.

 

I have a high flow APN header, stock downpipe, in to a 2.5" dual chamber Flow Pro muffler with no cat and it sounds great.