The Ford 5.0L/302 is a good choice because it is lighter than the Jeep six and the Chebby SB. It is a smaller package than both engines and it will develope as much power as you can dream up.
The Ford 5.0/302 is becoming the leader in new engine swaps and adapters are availble for any combination of engine/trans you can can think of.
I am new to Jeep but have been with Ford for a long time.
My latest project is a Bobbed CJ8 w/YJ nose, powered by you guessed it, a Ford 5.0L. I am using an Nv4500 trans, adapters from Advanced Adapters, so a Ford engine with a Dodge trans, see any combination is possible.
Lot of Luck,
Keep the Site informed of your progress.