There are still a few options.
There are portable AC units that stand on the floor, but they take up space. I've seen small window units installed.
My choice would be the RV rooftop model but would need to be wired differently because you are not wired in the ceiling. You would need to run 12 gauge Romex in a plastic stick on conduit (found at any big box building center). Then add a 20 amp
RV power inlet in the wall.
You could then run a 12 gauge extension cord to the 15 or 20 amp receptacle at the power pedestal.
I did this in a pop up camper.
Peace
Dave