I can't believe I wrote out a long winded post that didnt show up. OK, so in a nutshell, I can use my current inverter for power, I need to seal off and insulate the outside wall, I need to provide venting to the inside on the motorhome and I can spent 400-1300. Dollars and hope for the best knowing reliability will be an issue no matter the choice. Without Major work, the Haier unit is the only unit workable in the space getting the most cf so I'm pretty much locked into that unit. Would it still be advisable to exhaust with the help of fans , thus pulling conditioned motorhome air into the compartment and exiting as before through the roof vent? I would add venting from interior to accomplish this. Once again, thank you all for your comments.