Mike,
I was in your shoes some time back when I was looking at new trucks and after tent camping for years we wanted to go to an RV but we where thinking pop up or smaller bumper pull. So I bought a 2500HD Chevy with a 6.0 gas and liked the truck. Well a few months later we started looking at RV's and ended up buying a 32' 5th wheel. Everyone said the truck would pull it and it did but not very well. Fuel cost was so bad and hills where like 20-30 mph at the top. We wanted to go out of Texas to Colorado and at that point I told my wife we need a diesel. I took the 2500HD with a gas engine with about 40k miles to my Chevy dealer and I realized that HD trucks with gas engines are worthless so I looked at Dodge and they gave me the most and bought my 1st diesel. Don't get stuck with a HD gas unless you are keeping it for a long time. Towing with diesel is a real pleasures and I won't go back as long as I have my 5th wheel.
Good Luck