I highly recommend the 4wd. I have had to use it backing my tt into an uphill site on a gravel road on the side of a mountain. Remember that rig is heavy. The 5ers is heavy and the truck is front end heavy. I have even had to use 4wd just to back the truck up hill on gravel on my old F250. You will use 2wd 99% of the time but it sure is nice to have the 4wd that 1% of the time.
Get steps put on. Pay attention to what steps they put on. I got my dealer to install steps on my 2014 silverado 3500 and they only bought me 2 inches. Get steps that sir lower. I am only 5'2" and I have a hip injury. I am still able to get in and out of this truck without too much issue.