For a basic commuter, and it depends how you like to drive with acceleration or not, the 4cyl/auto will be a leisure accelerator. You will need to put your foot into it constantly to keep the momentum and speed. I've got a 97 4cyl/auto. It is your basic TJ with vinyl and nothing else. It was soft top and 1/2 drs. Got it 5-6 yrs ago for $3600 out of OH. 125k miles.
For a commuter, I'd suggest 6cyl. For the mileage you'll be traveling (40), keeping your foot into it or manually shifting to keep accelerating, you won't be the 1-2 mpg difference than that of a 6cyl. I've got 35s and 4.88s. I'm a little high in rpm compared to stock by 200+rpms. But I get 13-15mpg on a real good flat highway run with a slight tailwind. I really can't accelerate past anyone and forget about going up an incline. The 3sp auto does have the lockout tc and that is another 2-300rpms lower.
For your camping travels, bet you'll be pulling a small trailer or having the Jeep packed with equipment. Adding weight to the 4cyl will hinder its capability as well. For the travel distance you have for camping, why not look along the route in CL? for something? Also, check with CarMax as they have non-negotiating pricing so you really can see what they have for what cost. You can also get a vehicle from one Carmax delivered closer to you for pickup. They have their own transit/shipping service. CL is a good way of getting something, but figure, you are looking at something nearly 10 yrs old. You can get a good buy as well as get a bad one. Being that old of a vehicle, do you want to carry a loan or have it clean and clear? Are you mechanically incline to be able to repair the Jeep or would you need to get a mechanic?
If anything, go take a look and drive it. Look for traffic to simulate a traffic environment you'll be in mostly with it.