I am doing the exact same thing--I hope.. I have the 285/75/16's now --BFG All Terrain's--which are about 33x11.50 x 16.
I ordered the rims 16 x 8 with 5" offset 6 x 5.5 bolt pattern.I hope the 5" offset is okay because like you the price was realy good.I'll know in a few days..... <img src="/forums/images/graemlins/kewl.gif" alt="" />

1997 Wrangler TJ 5 speed, 2.5 L. Mostly stock except for 31x10.50's on Black Rockcrawler Rims.
1998 Wrangler TJ 5speed, 4.0L. Rusty's 3.5 " lift,33"BFG,4.10 gears,Novak transfer case shifter