You have defined some things you want a vehicle to accomplish. I will challenge you to consider the type of vehicle capable and your expectations.

Now, dependable and easy on gas. There you are creating a conundrum. As your other expectations dictate capabilities that are going to require a trade-off.

With that in mind, MY major criteria is on dependability. That beings to limit vehicle type to one whet repair parts are readily available when outside a major metropolitan area.

Don't need electronic gadgets - good choice as dust and electronic controlled mechanics can be a problem.

You want something that will drive through sand, rivers and climb mountain trails.

With these criteria, you are defining vehicle capabilities the dictate lift, lockers and tire size. Here comes a trade off, those will affect mileage. And, many of the electronic packages can be a problem in adverse conditions.

In my opinion, you are looking for a moderately modified vehicle that has a mild lift to provide ground clearance. Ground clearance and traction are important criteria to consider. Along with ground clearance is increased tire size which dictate an appropriate change in gear ratio to accommodate the extra engine effort.

At the end of the day, you are looking for a Jeep or Toyota that has been modified to provide for lift, lockers, and gearing. But, I would not rule out a MItsubushi Montero.

There are a lot of options. Based on your criteria, you are looking for a short wheel base vehicle that provides ground clearance and is dependable. The weak link is dependability. And, dependability does include consideration for electronic packages which are a failure prone option.