Some good stuff here - thanks! My current 150 EB has no engine braking to speak of, but uphill is no problem and it runs strong at 2500-3000 RPM. I've towed the same TH with a 3/4 ton Dodge Cummins, which was a more stable and relaxing TV esp downhill. I do a lot of hills in Oregon, mostly small ones, and I like to lower torque curve of the turbos (diesel or gas). I don't like to listen to a gas V8 run at 5-6k RPM to be in the meat of the curve. So the EB (470 ft lbs) or a diesel will fit the bill.
I have 8x 2 megawatt Cummins deisel gens at my shop so I know the costs of maintenance are up there. But I also have a lot of free motor oil laying around. ;)
I'm leaning towards the F-250 diesel. The F150HD is very hard to find (I found 1), and I think either way I will need to order to get what I want. I do NOT want the FX4 package, and I DO want the Tow Tech package and that's been difficult to find on a F250 Crewcab.
OP Mike