Hmmm, not sure on the cali legal deal. You'll have to make the call. I always recommend Hughes for Magnum motors. Their stuff is top shelf.
If you plan on keeping the keg intake be sure to do the plenum plate & gasket. The Magnum motors were notorious for blowing the factory gasket & burning oil as a result. So bad that Chrysler put out a recall on them. Here's the kicker, instead of fixing the problem, Chrysler just re-flashed the computer & retarded the timing to get rid of the associated pinging folks were getting as a result of a blown gasket. You can read all about this online. It's called the death flash. Death flash because it makes the vehicle a gutless turd. A re-flash or a programmer such as hypertech or superchips is the only way to get rid of it.
A set of Harland Sharp 1.7 rockers are a great investment. Well worth the money. The factory cam in the Magnums is a lazy cam, the 1.7's wake it up a bit.
A 50 or 52mm throttle body is a good power adder, but i wouldn't mess with it since it'll raise the power band up. Since it's going in a Jeep you'll want the power band down low. The original TB will be fine for that.
Anyways, there's lots of stuff out there for them, you'll just have to dig on the internet to find it. Magnums are the black sheep of the big 3. Not as much support, but it's out there.