They aren't bad vehicles, but keep in mind its a 10 year old Chrysler vehicle with an Italian engine, so unless its already had a bunch of work done, it'll most likely need a lot of maintenance stuff. Timing belt and water pump is $400 in parts every 100k, seems like head gaskets can fail anytime over 100k due to the factory TTY bolts like the 6.0h, studs are $350ish. Rocker arms are known to fail as well and require pulling the cams and everything off, i think they run like $200 for all 16. Then you still have the rest of the vehicle which will probably have some issues. Luckily i got mine pretty cheap so i was expecting it to need some work, and even with everything i've done including new tires, all the mods, timing belt, etc... i still have less than $4500 in it total.
But they are kinda fun to drive, get decent MPG's, have a manual t-case, and they get some attention because of how it sounds. I was sitting in-line at a Wendy's one day in a local ag town when an older man and his wife came out. He started walking in front of the Jeep but i noticed he immediately heard something off, saw my turbodiesel badge and had to do a double take. LOL
I'm not sure yet what i'd do for a converter, lot of good and bad reviews on both the "euro" spec converter and the hemi converters. Seems like the only really good ones are the Suncoast converters, but no way in hell would i spend $700 on a converter that will never see more than 250hp/450-500lb-ft.
BTW don't price lifts unless you want a heart attack, to properly lift a CRD with good parts you'll have $850 in new springs and shocks. And thats just to get 2.5" over stock.