RV.net has a dedicated forum to dingy towing. You might get a wider knowledge base access there:
rv.net dingy towingMost Jeeps can be flat towed - check your specific year to be sure.
Two door vs four door: The two door models have a tighter turn radius which can be advantageous in getting around trees, rocks, holes, etc when off road. The four door is a bit cumbersome for that kind of off-roading.
Four door has obvious increased passenger and material carrying capacity.
Follow the link above for additional specific equipment needed for auxiliary braking systems.