If you don't want tires as aggressive as the BFG AT, they also have a less aggressive tread tire called Rugged Terrain. You can go to tirerack.com to see the reviews on different tires and how they perform.
Going to a larger size is less expensive and quicker way to change effective gearing. The 3.0L engine likes to rev to make power and going to the taller tires will drop those rpms and will result in reduced acceleration. However, I think 4.10 gears with 31" tires is a good balance. I had and 89 STX Ranger with manual transmission that had 3.73 gears. When I went to 31" tires, that 2.9L engine kind of struggled with it. I went to 4.10 gears and that made a big difference and made the 31" tires work well. BTW, they were BFG TA tires because I like to go off-road a lot.
2002 FX4 Bright Red Supercab 4.0 SOHC, manual 5-spd & Tcase, 33" BFG MTs, K&N air filter, Modified air box inlet, Gibson SS cat. back exhaust, Bama flash, Hidden Hitch round receiver, Rear helper air springs, Electric trailer brake controller, Line-X bed liner, WAAG bar with KC lights and Wildernest shell.