I believe you could save some money by having the precats cut out and replacement cats welded in. Replacements could be Magnaflow universal cats which can be had for about $100 or less each. It would not be a big job for any decent muffler shop to do the cutting and welding.
If you decide to try to do this, email Kolak (firstname.lastname@example.org) for a price on the appropriate universal cats.
2001 WJ Limited with Quadra-Drive, Kenne Bell Supercharger, 3-inch Kolak exhaust, Stillen rotors (F/R) and MM pads, Addco sway bars (F/R).