I need a "new" truck

A big old truck is cheap. Considering the miles you seem likely to drive.
In my experience a diesel properly rigged will get about 25% better mileage than a adequate gas engine, twice that of the BIG gas engines.
With in reason heavier makes little mileage difference SPECIALLY in the work you listed.
LONGER tends to be more stable.
With that in mind Id look for a 305-351-360 size gasser in a crew cab one ton.
a 3/4 ton would work fine too just a little less brakes.
As for 4WD LOL you know if you needed it on your last rig, if not it will save you money and gas not to have it.

I live in the extreme salt belt. My next truck is going to be either from western Canada or the southern US. It will likely be 4wd (we need it here) and will be pre 1984. No computers to worry about- a carburetor, simple distributor is what I want. Easy peasy to fix, parts are super cheap. If you buy a popular model like a Chevy or Ford you can get EVERYTHING from sheet metal to upholstery brand new. I'll keep it well protected with Fluid Film and I should get several years out of it. Also, keep in mind most newer trucks have tires that are 17-20" in diameter. These tires are really expensive. The old trucks had 15" tires which are still available and much cheaper.

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Located in beautiful Prince Edward Island