What should you grab? Everything he's getting rid of. The best idea would be to pull the grill off and pull his whole drivetrain out and drop it into yours. It should bolt up, even the exhaust. You will want to check and see if your old emissions stuff is the same, if not grab his Evap canister and lines as well. You'll want to check the fuel pump pressure to see if it's OK. I'm sure it will be lower then the MPFI's though. Might have to go with an inline setup since he probably won't be giving away his tank. I'm sure his harness will be a bit different then yours. You could either upgrade your vacuum disconnect to his, toss it or adapt yours. You'll have to double check the pinout on the harness to make sure all the gauges will work.
Best thing to do is set the two Jeeps side by side and start pulling parts and swapping them over till yours starts.