Depends on how much you use the jeep onroad and off, how important the 'appearance' is, and how high a risk you have of tearing up rims or blowing a bead while wheelin. Everybody's situation is different.
If you like the wide appearance to the wheels, and aren't worried about rim or tire damage offroad, then go with the 10".
If appearance isn't a primary concern, and you want something reliable offroad, use the 8" rims. The majority of jeepers around here with 12.5" have them on 8" rims. Some have learned the hard way to not use 10" rims.