You dont want a 4cyl, I wouldnt anyway. But whether you get a inline 6 or a V6 depends on what year you go with. Up the 2006 used the inline 6, 2007-up used a V6. 4cyl not offered after 2006. If you go with inline 6 stick with 1997-2006, they have coil spring suspension front and rear. Before that they are leafs front and rear, ride is a little smoother with coils. As far as wich motor is better, both the 4.0 I6 and the 3.8 V6 are good motors so it is a toss up really. But I do seem to remember a couple years they had problems with the head on the 4.0, dont remember what years 99-00 I think.
But I would suggest an early Bronco, much cooler ride than a heep.lol I love the early Broncos.