If you were buying a new tow vehicle tomorrow...

I have 2 answers.

If "reasonable" budget allows for brand new, then I'm pretty much copying off ib516's paper. The only difference is, for A), if the rear air suspension is only available on a Ram 2500 (not 3500) then I'd go that route; for B) I'm taking the '14 CTD with 4.10 gearing.

Now, if reasonable budget is considered to be late-model used (but not new) my answers change.

A) 2010 F350 SRW CC 4x4 V10 4.30 gears
B) 2011 GMC Denali DMax CC 4x4 DRW