Found a long bed TC hauler.

Looks awesome and one of the best trucks out there still IMO. There was some LLY engine overheating issues. Maybe read up on that on a Duramax site to make sure you're taken care of. Otherwise a pretty bulletproof hauler.
As bedlam said look at what you need to shore up the ago end before plopping a camper on it. Sway bar, helpers or airbags and good tires. Don't know how heavy your camper is, but my AF got set on the same rig with airbags and ran the Denali hwy caribou hunting the next day. Don't get much heavier than the AF campers.
Congrats. I had an 02 DMax that I loved.

Nice truck - I have the same year although a different brand. Look into the larger tow mirrors so you can see along side your TC. Once you have your TC loaded, you will be able to see what suspension upgrades will make it feel comfortable. Does it have helper springs or an anti-sway bar installed?

https://www.gmupfitter.com/files/media/photo/111/2005_LD_CKFullSizeTrucksPickups.pdf

I think you should pass and get a 1 ton truck. A truck with 8800 lbs of GVWR that already weighs over 7,000 lbs empty is not the ideal for carrying a TC.