You could get lucky with this type, and find a mobile home unit that has an A-coil in it, nd have best of both worlds, heat and ac. Older trailers, are always usable doners!
Also, could go to WalMart, Home Depot, Menards..ect and get a couple rolls of plastic sheeting. Tack it up on ceilings and walls that are drafty. Will keep a little more control of the heat and cooling.
