Possibilities. I don't know if you have fifty amp or not. If so check with the mfg about an existing hole and wiring covered over.
Our HR had only one air but had wiring and breaker and area in roof for a second air.
I saw a site, last night on the net about surplus RV items. It had new 13,500 units for six something and 15,000 btu units for 165.00 or so more. A couple of the new ones, were advertised with 1/3 hp fans that were supposed to really help with cool down. Don't know if one of them was on the surplus site. 30 Amp will handle  one ac of either size.