Unless you are planning to tow a heavy trailer at the same time, the gas engine will be overkill.
Yes, it will run at higher RPM compared to the diesel but it won't hurt the engine.
Yes, torque is nice but it's torque AT THE WHEELS that counts. The gears in your truck can multiply that 400ft-lbs to get a lot of torque at the wheels.
Also torque only determines IF you can climb the hill. HP is what determines how fast you climb the hill.
If you just want a diesel to sooth your ego and money isn't an issue...go for it but from an objective point of view, it's a waste of money.