Parts I've installed are in my signature.... 50,000 miles since install. Had a wheel bearing fail about 1000 miles after installation, which I do not attribute to the lift, as they have been fine since. The biggest, most common issue with the 6" kits are breaking transmission mounts. They are extremely easy to replace, but are like $80. The common fix to prevent this failure is a set of traction bars, most have used the ones available from PRG Products, although several other options do exist.
The only other item which has failed on me is one of the four CV boots. I cannot say with 100% certainty however that that was a result of the lift.
As far as parts go, I would recommend exactly what I have listed in my signature, and additionally, a set of SAW's in the back, along with a Deaver C30 spring pack and 1" block from PRG Products.
Additionally, I would also recommend the PRG 4" Performance Package for 4x4's.
PRG Products.... call Greg (the owner, installer, shipper, manager, marketing guy, janitor, salesman, & engineer, among other things) he will guide you through exactly what fits your needs. He can be hard to get ahold of, so it's best to reach him at 7AM Pacific Time, when he first is out in the shop.