Wow 14" rims are becoming obsolete these days. I would highly suggest going to a 15 or 16 inch rim to really open up your options. There are plenty of used factory Isuzu wheels to be had.
Otherwise go to tirerack.com and use their system to hunt down what your after. I bet the BFG radial T/A comes in a 14" with a fairly big OD like 26" or 28"
1990 Trooper, 3.2L (3.1L .040 over) Pushrod V6, 5 speed manual. 33X10.50X15 BFG M/T KM2's. 3" OME Lift. Cowl Induction Intake. ARB Lockers front and rear. HD Tierods.
Off the road for an overhaul right now.Big Bore Intake Kits & Greasable Shackles Here