Without the need for towing heavy loads you can stay with the 1500 and include the HD trailering and HD cooling packages and should be able to keep decent fuel limeage and do everything you need. with the HD cooling you get external oil and trans coolers, hd radiator, 6 speed trans, and with the stabilizer from the hd towing and stiffer shocks, you should have no problems. These added features should help reduce wear on powertrain components. Only issue I see is that this all comes with the 3:42 gears. If you want the 3:73 you have to go with the MAx trailering package which has all the other stuff, but also comes with the 6.2 L engine. benefit is more power and torque, but the mileage will be more like that of the 2500 HD just in a 1500 package.
Either way you won't need the Duramax/Allison combo unless you have extra money burning a hole in your pocket and just don't want to ever need to replace your truck again. A great option is you have the $ and want to go diesel.
Only issue with airbags is that under extreme loads it puts a lot of pressure on your 1500 frame. If it's just to level the load on a within limits pulling situation they're great, but if you're talking payload I wouldn't do it. I have heard of people using them and experiencing bent of broken components because the frame wasn't rated for what they were loading them down with. In your situation they would be a bandaid (with risks) and not a solution.
Either way you won't need the Duramax/Allison combo unless you have extra money burning a hole in your pocket and just don't want to ever need to replace your truck again. A great option is you have the $ and want to go diesel.
Only issue with airbags is that under extreme loads it puts a lot of pressure on your 1500 frame. If it's just to level the load on a within limits pulling situation they're great, but if you're talking payload I wouldn't do it. I have heard of people using them and experiencing bent of broken components because the frame wasn't rated for what they were loading them down with. In your situation they would be a bandaid (with risks) and not a solution.