First, welcome to RVF. Now, as to “pulling a 7,000 lb trailer out west,” here are my thoughts.
Then, I don’t think any 1/2-ton truck makes a good tow rig for anything beyond a small boat, camp trailer, etc. The suspension is just not robust enough to provide good handling and stopping. Now, every truck salesman you talk to will tell you the opposite; but, they are in the business of selling trucks! Let’s remember that towing a trailer is not about how much you can pull; it is also about how much you can handle and stop safely.
A couple of other thoughts. The “7,000 lb trailer” will most likely be a 9,500 lb trailer when you get it loaded with food, water, propane, clothes, pots/pans/dishes/etc., and “toys.” That’s not an exaggeration; it is pretty easy to put 2,500 lbs of stuff in a trailer. So, the question now becomes “Would this truck pull a 9,500 lb trailer out west?”. And, at least for me the answer would be “not safely.”
While “out west” is a pretty general description, I think you may be asking about traveling in the mountains…big mountains. We do have some big mountains out here in the west. Your truck would probably pull that trailer up most grades out here without too much trouble, though some long, steep grades might have it breathing hard. Going down the other side might be something of a white-knuckle adventure, however. I wouldn’t be comfortable with the braking capacity of a 1/2-ton truck on some of the long, steep and sometimes winding roads and highways out here. Sure, good trailer brakes will help but I think you would be on the margin.
Going with a lighter trailer (not more than 5,000 lbs + “stuff”) might be doable, however. The mistake most folks make is in trying to fit a trailer to an existing vehicle. The better approach is to select the vehicle to be towed first and then match the tow vehicle capacity to it. There will be some difference between towing capacities for a straight-pull travel trailer and a 5th wheel, but with a half-ton truck it won’t be that much IME. Of the options you mentioned, the Class C towing a small car might be the best choice.
TJ