I have SCT
for my 5.2L ZJ. My butt-dyno isn't very sensitive, but I'd say I noticed an increase in power. I definitely noticed a difference due to the removal of torque management.
I got mine through Sean Powell, firstname.lastname@example.org
He has had a sale going on for a while, I'm not sure if it is over with or not. It was $250 for the tuner and three "canned" tunes or $350 for the tuner and lifetime custom tuning through him. If you go with the custom tuning you will want to pick up a wideband o2 and data logger so you can emial him the data and he will tweak your tune. His regular price was $450 & $550.
You’ll probably want to pick up a 180deg t-stat. Beyond that the basics are 52mm TB, modify the intake manifold, headers and high flow exhaust.