I have added one on two different DP's. No extra support needed. Remove your rear exhaust fan and install AC. Buy one that does not use the ductwork and has controls on the unit. I ran my wiring on a #10AWG SJOW cord on the side of the MH so I could plug directly to the pedestal via an extension cord. Now when I go to a CG with 30 amp only, which is often, I can have this AC separate from the 30 amp plug, or when on a 50 amp I can plug to pedestal and have 3 AC's if needed. This settup really does work well.
The hardest part was having my wife carry the new AC up the ladder.