Good choice for what you'll be doing. But the 6.4 is no slouch. I pulled with it for the first time last weekend. I was not going on any highways, so i kept it locked in M4 so all 8 holes stay lit all the time.
Up in the mountains, on the steep grades, i got on it enough to kick it down to 3rd gear. It went to about 4k rpm and wow did she pull strong. I had to back out of it because i was accelerating too quickly, up hill!
Its a great engine. But like anything else has its limits. Id say 10k and under trailer weight, its a great choice. All trucks hold their value well, including gassers and half tons. Just my .02
Again, great choice and best of luck