For the weight you are talking about I would seriously think about a medium duty truck. Like you I have pulled 20K with trucks that are rated to pull half this (i.e.older F-250s), but my F-800 does it much more comfortably and with less drama. I also know that with the F-800 if my trailer brakes fail that it will not take to the other end of the county to get stopped.

 

NOT A BAD IDEA.
But what I did was I found a 99 Dodge Ram 2500 QC 4x4, V10 5 speed with 72,000 original miles from the original owner & made him an offer of $5500 a little over a years ago. I pull a 10,000 TT with ease. Get about the same mileage as a 6.2L gas Ford. The best part no (car note) or high license or insurance.
I have other than a few minor things (ABS sensor, T-Stat & gasket, washer bottle) just did a complete maintenance update.
Dodge in 99 did not make a 1 ton SRW 4x4 But this one is optioned out with 1 ton suspension. Dana 80 rear Dana 60 front, Heaviest GVW, the heavy sway bars etc.
I don't know what you have now? But it would be interesting to know what you have plus what you want to do.
Craig

 

I just got thru pulling my 24 GN with pallets of rock. I was only on back roads running a 30 mile round trip. lots of curves ranging from 40-65 mph. didn't have any problem - standard weight - truck& loaded trailer was 23,500. Made 7 trips. not an issue at all. the first load I was up at 27,600 and took it easy as I was on dual 7k axles and tires only rated for 4200 each.. truck/motor had no issues - just worried about the tralier...

I don't do that all the time but the truck doesn't seem to care when I put weight behind it. My weak link is my trailer - it is a little heavy empty weight - but with 8600 lb skid steer/ attachments it pulls well - weight police might not like me though..