Many of then will do the job just fine. I would look for a 6 speed model which would exclude the 8.1 GM.
The 6.0 GM would probably be my optimal motor. It gives you room to grow if you upgrade the TT and they are reasonably priced right now. The 5.4 Ford is a reliable work horse and will get the job done. It's just not as powerful as some of the other options and is overshadowed by the 6.8 thirsty beast.
Also, if you think the 6.0 failures are bad you should see what happens to a 6.4 PSD when it blows an EGR. Anyway, not trying to fear manger, just thoroughly research.
If you want a diesel, and it kind of sounds like you do, buy the Duramax, Cummins, or the 6.7 Ford.
Thanks,
Jeremiah