As far as the lug pattern is concerned it's 5 on 5.5 :
Jeeps with 5 on 5.5" Bolt Pattern:
* 46-86 CJ (All Models)
* 63-73 Full Size Cherokee/Wagonner (SJ)
* 62-71 Galdiator Series Truck (All Models)
Not sure about the offset between different models.
If you are not going stock, 5 on 5,5 is also the same lug pattern as on early Suzuki Samurai's, if your looking for something different.
Largest tires you can fit without lift and clearance issues is 31 x 10.5 i believe, not entirely sure on that one though.