Actually, 10cent, that was originally one of the options my exhaust guy was going to try. He was going to either cut up a set of LX JBA shorties (uncoated stainless) or try to get JBA to sell him the unassembled header flanges and tubes and go from there. Once he got the WK apart he decided it would be quicker and less hassle to just build them from scratch. I think he would reaccess that now that it's done. I think the only way you'll find out for sure is to get a set (either the LX manifolds or the shorties, or both) remove yours, and see what needs to be changed. It has been tried so you may want to check here: http://www.jeepsunlimited.com/forums/showthread.php?t=527426
You'll see that he ended up using the stock SRT manifolds, but not without some big issues. I opted against that because only 2 sides of each port matches. The SRT header hangs over the other two, which would create a big obstruction to the exhaust flow. Also, the EGR issue is a biggie, IMO, especially if you're in a state that does emission testing. It's actually better to have the EGR, because it lowers combustion temperatures, and can give you a little more power with less chance of detonation.
My system has custom built tubular headers and a custom 3 in. system utilizing in this order behind the Cats: a 3X10 in glasspack, a 3X22 in. Magnaflow muffler (No. 14589), and another 3X10 in. glasspack in the stock resonator position. This keeps the Hemi MDS drone to a minimum, and allows it to pass the "wife" test. There is minimal tone note change between 4 and 8 cylinder mode. The headers with the 3 in. system is waaaay to big for the 4 cylinder mode though and probably looses power because it can't scavenge like it should. That's also why additional glasspack sound dampening is needed.
Hope this helps you a little in your decision making process.
Give one, or both of the options a close look and let us know how it comes out. A bunch of us Hemi owners have inquiring minds and want to know. I will say it's a tight fit up in there, so you'll have to take your time and be patient. When I saw what the exhaust guy went through, I was glad to pay him. Even though the price was fairly steep, I feel I got the better end of the deal. He was real good about it though and, because of it, I'll always take my work to him. Besides he's the only quality custom builder in town.
06 GCO, Dk Khaki, QDII, Flshing Hi 3rd Bk Lt, MDS "ON" Lt, Airtab Vortex Gens, Debadged, Fumoto Drain Valve, BT Catch Can, Chopped EGR Tube, SRT8 CAI, K&N Filter, Sonnax Trans Line Press Booster, SC Tuner W/Adv Trans Tune App, DS Tuner, Cust tubular hdrs w/3 in Magnaflow/Xlerator AP Exh Sys, Bilsteins, SRT Springs/Sways, Cust Eng Cvr, SRT8 frt/rear bumpers, FRI Sidewinder Cam/6.1 valvetrain, SLP 25% UD Pulley, BBK true 90mm T-Body, SOS Ign Coils w/.060 spark plug gaps, SRT Reps with 265/45&295/40X20's.