My brakes have squealed for the longest, I'm positive it isn't the front, but the rears. I have a 01J2 with drums in the rear. In the front I have used Akebono ProAct Ceramics which are awesome, and Wagner ThermoQuiets which are pretty good also (I think the Akebono were crisper for stopping). I'll be having a set of thermoquiets installed in the rear soon. They were squealing horribly until I cleaned the rear drums out, then it gradually came back.
Pirelli Scorpion STRa are very smooth tires. You'll get plenty of recommendations for tires and such here. Tires, followed by good shocks, and an upgraded rear sway bar with urethane bushings (www.explorerexpress.com) will make the total difference, search for either of those on this site for plenty of hits.
Changing my front sway bar bushings with urethanes from energy suspension helped also. The stock bushings are urethane, but my 2 main ones were worn out.
Shocks and Tires will make the most noticeable improvement. I had installed the Pirelli's over the crappy Goodyear RT/S tires when one of the GY melted on me. Big difference right away, then shocks, more improvement, then sway bar upgrades.
The sway bar upgrades are only noticeable in cornering, and when you hit a bump on a curve at hwy speeds. It will ride on rails, and won't kick out in the back when you hit a bump on the hwy.