I went through the same thing when I bought my YJ 5 years. After pricing the parts and calling a local exhaust shop it came out cheaper to have it done at the shop with a lifetime warranty (going by memory I think they charged $90 for a new pipe from the cat, new high flowing muffler, and tailpipe with a lifetime warranty on the muffler.) My advice is check with a local shop or two (I am not talking a chain shop like midas but a local shop.) I never take my vehicles to shops but when it comes to exhaust I always get frustrated and it usually works out cheaper to have it done.
1990 Jeep YJ 4.2
Howell EFI, BDS 3.5" lift, M.O.R.E 5/8" Boomerang shackles, 1" Daystar BL, 1" JKS MML, TFI, Crager soft 8s w 35" Dunlop Mud Rovers, Ford 8.8, 4.10s, Dana 30 E-Locker, Terra Flex SYE, Tom Woods CV shaft..