Another thought on dual tires: I'm not sure how much weight you're allowed to put on an axle with single tires where I live, but I am sure that it's far more than any one ton will ever carry.
As for automatic transmissions: I don't think a finned sump does too much good for cooling. In an oil filled sump, increasing its surface area isn't the best way to increase the heat emitted on account of a cooler, more viscous layer of oil against the relatively cool sump inhibiting heat transfer. One book I read suggested that on account of this problem, fins on the inside would be more effective than on the outside.
I don't mean to say that a finned sump is useless, just that you'll get better performance by plumbing an aftermarket transmission cooler....If you have enough in the budget for a cooler AND a finned sump, then I think you should definately buy two coolers.
As for 4x4's, I say don't get one if you don't need one! That front axle and transfer case are a lot of weight to be hauling around if you'll hardly use it.
Engine wise...sure, you don't need a diesel, but new diesels are very easy on the fuel when you consider the performance you get. As for the Ford V-10, a former boss of mine had one in his truck. It pulled nicely...he could pass anything but a gas station!