I thought I recognized a CJ I6. Good motor IMO.
I bet a 2 barrel would be good enough. Now I can't remember what we have on ours.
A friend of mine has an old ford F150 with the 352 and it came with a 2 barrel. But I think he upgraded to a 4 barrel, it was also a bigger motor. So I would go with the one that has the most bang for the buck.