Well this topic will be interesting
here was my thought process When I was is in the market last year I looked at gas diesel truck and suburbans. By far a 3/4 ton is a must a 5.3 in our tahoe has plenty of power to pull my 26 ft enclosed. However the stability and braking is marginal. So 3/4 at a minimum.
The power of a diesel is by far the best but given 4 trips and the initial cost and maintenance I am not impatient that every incline requires 80mph hold. So back to gas.
In the GM world this leaves 2 choices 6.0 or 8.1. I found the 8.1 sits right between the Xmas and 6.0 for power. Withth a cost advantage over the Dmax and power over the 6.0. Also found that the fuel mileage is better overall than the 6.0.
At the end of the day have by a family and a tag trailer pushed me to yukon xl 2500 with 8.1 i have the 4l80e but there was an Allison option.
Again this was my tbought process. I did like look at dodge and ford. A diesel excursion would have been great but wast able to locate one that fit the bill.