I might add - if I were just starting to build, I'd absolutely try and keep the additional weight down and keep in mind the MPG hit of tire size, lift height, etc.
Even if the money doesn't matter, the range ABSOLUTELY does. Like I mentioned above, my Jeep only has a range of 360 miles (without carrying extra in jerry cans), which is actually a LOT further than most Wranglers. But I'm frequently bumping up against that range limit and having to make logistical decisions about whether to carry extra fuel in jerry cans, which I hate, or detouring to pavement and civilization for fuel, mid trip, which I also hate.
More range is absolutely a GOOD thing and I'd definitely make it part of the plan when starting a build. I'd save weight anywhere I could. Spend extra on aluminum to save weight vs. steel anywhere it was appropriate. I'd keep the lift as low as possible for the required tire size, to include fender trimming and/or high clearance replacements. All in the name of MPG. Even 1 MPG, makes a worthwhile difference in range. Getting an extra 2 MPG in my Jeep, would give as much more range on a tank, as carrying an extra 5 gallon jerry can. It adds up.
But, I'd also factor in the need for a larger, or aux. fuel tank and probably the ability to carry extra fuel in jerry cans as well, unless the tank(s) alone get you enough range.
In other words, I'd hit it from both angles. Maximize MPG as much as you reasonably can without sacrificing adequate capability and reliability, but also increase fuel carrying capacity. I think that unless you are going to be doing stuff in other countries where actual expedition type stuff is possible, getting your range to about 500 miles is sufficient for just about anything you'll be doing around here these days.
All of which, is going to cost more money, that you'll never make up in MPG savings - not in a million years. But, my experience, fuel capacity/range is a big factor in how trips need to be planned and in my opinion it really sucks when your range causes logistics requirements that you'd rather not have to deal with. More range is a VERY GOOD THING.
- DAA