I recently purchase from them and had great service. They were far cheaper then I was able to find local.
The aluminum you want for that vintage is T2024-t3 Alcad. It's around $12.5 a running foot (4ft wide).
For exterior pannels you want .030. For interrior and belly pan you want .025.
If the door is like mine and really messed up it would not be hard to skin the door. The only special tool needed would be a Bead roller to put the bead back into the lip. They are not super expensive and can be bought at www.harborfreight.com
or Eastwood. If you check with your local hot rod shops you might find somebody loacal that does interior aluminum pannels and they would have a bead roller. Take about 30 minutes to do and probably only charge a few bucks.
Do a search on "Door Knob" as well. Depending on the style your coach had there may be a reproduction available. That should pull up most of the post on the subject and one of them will have contact information on reproduction handles. Won't be cheap.