Did you try www.thetirerack.com? They have a pretty good website with good pricing and you're able to specify what type of tire you want. Or, try calling them directly. I've always had a very good experience with them.
1998 K2500 Suburban 6.5L TD 3.73 rear, Ron Schoolcraft 18:1, Kennedy ECM & IC, Timing gears, Splayed main caps, 3.5" Kennedy Exhuast/No Cat, K&N Filter, Boost/Tranny Temp/EGT(Pre Turbo), Ceramic-coated Manifolds, 195 Stat's, 265/75's (VSSB Adjusted) 7,000lbs (on a scale) Remote Mount Oil Filter, Remote Oil Pressure Sensor