Fuel prices are chaotic and will stay so for quite a while. There is an effort to drive them up even further. Many of refineries are setting themselves up to better handle diesel and more diesel pumps are becoming available.
3/4 ton gasser would do a good job for you. 3/4 tons are pretty good, depending on model, to pull a 10K trailer.
Gasser or diesel, 3/4 tons are beefy. Great brakes, better tranmissions, 4WD sometimes. The mechanic says they are real trucks and have long lives too.
If you are going to stay under 10K for your trailers, a gasser can probably do well for you. The more time you are going to stay around 10K or more diesel is a better way to go. If you are planning to take on the mountains out west the turbocharged diesels are really great.
The diesels to avoid were the transition years on emission systems. That varied from manufacturer to manufacturer. If you buy outside of that range reliability was much better. Some of Dodge's problems were that the owners did not drive the trucks hard enough and long enough.
I would also agree if you are driving light, not far, or not high a gasser is probably the best way to go. The cost differential is moderate and you may not miss the performance.