bdog
You are correct in your assessment of "holding up" when worked hard. For one thing, take a look at the aftermarket for "beefed up" GM steering components. Tons of them, because some of the components are just plain weak, especially when used off road a lot. Around here, the true diesel fans drive a Cummins, the workers MOSTLY drive fords, and many folks (like me) that use them for RV hauling and regular drivers, drive GM's. That's just how they go.
Every model has it's strong and weak points. I'd like the torque of the Cummins, the ride of the GM, and the reliability of the Ford (just the truck, their past engines are another story), to make an ideal truck.
So it would have to be a Ford body, with a BEEFY strong front end with independent front suspension, and Cummins 6.7. With the current crop of 6spd transmissions it's probably a toss up there, but it would have the acceleration of the GM or maybe Ford (never driven a Ford 6.7). There ya go, somebody build one and call it The ULTIMATE DRIVING MACHINE, oh wait, that handle has already been taken. How about the ULTIMATE TRUCK?