I currently own a 2008 Tundra 5.7 CrewMax SR5, a 2005 5.7 Power Wagon Quad Cab, and a 1998 5.7 GMC K1500 Z71 Extended cab, all gassers and all driven hard. In the past have owned other trucks from Chevy, Toy, Mitsubishi, Mazda. The Dodge is, by far, the absolute best of the bunch. Not only the most capable but the most reliable. The Tundra feels flimsy compared to the GMC and the Dodge. Example: Three weeks ago some kid hit the Tundra while it was parked. He was riding a bicycle. Tundra goes to the body shop tomorrow for $2300 worth of body work. From a bicycle. Tundra gas mileage is horrible because the SR5 only came with a 4.30 diff in that vintage, but truck has lots of power and a nice interior, offset by that ************** 5.5 foot bed. Tundra has had some electrical issues that required a new, very expensive, body module. Toyota parts are very expensive. Tundra handled like a pig until I upgraded the shocks and leveled the front. I hate leveling kits, but the Tundra needed it to shift some weight off the front end. Back end is always tail happy, even with the leveling kit. Very nice highway cruiser.
The GMC is pushing twenty years old and I just keep dumping money into it because it does what it does pretty well when it's actually working. GM quality was horrible until I upgraded a lot of components to make it into a work truck that could go offroad. But stuff keeps breaking and/or wearing out. Cheaper to fix it than to get a new truck, but I'm pretty well turned off to GM products.
The Dodge is a 5.7 Hemi on the 2500 platform. Gas mileage sucks. That's my only complaint about the truck. Over twelve years, the only repairs have been a broken CD changer and a broken exhaust stud. Everything else has been normal maintenance. It does need a new transfer case position switch to make the dash light go out, and that part is sitting on the passenger seat, cost $84. Best truck I have ever owned, and possibly perfect for OP's needs. So my advice is to think about a 3G Power Wagon.
I would avoid anything from Ford with an aluminum body and/or an EcoBoost engine.
If you really want a "heavy half," that's what Nissan is marketing the new Titan XD as, but they are very expensive, have very compromised resale value, and I am hearing thru the grapevine about a lot of issues with their new diesel engine. The other obvious (at least to me) alternative would be a Ram 1500 EcoDiesel with a few mods. I'd look for the best 3G Power Wagon that you can find. Big diesels from any manufacturer are overkill for OP's situation.
