Spend the money do it right the first time. Coilovers all the way. They are super easy to get put under the truck, the hoops are easy, the springs are easy and everything is easy on them. full adjustable, rebuildable, everything. They are stout too. I prefer Sway-Away Racerunners but you can run Fox if you want.
I have had both in my hands and I think Sway-Away is a better shock for the money.
No way would I ever touch leaf springs, its old technology, kills approach angles and just not the best. With a little bit of work you can toss in a good 3 link or radius arm setup and it will run great down the road and impress people on the trail.
2003 Ford Ranger Lincoln Powered 5.4L DOHC, 42s, COs, D60s, 203/205, 4points, caged, full hydro, 3link front and 4 link rear.
1998 f150 bone stock baby hauler...