Heating and Cooling 120sqft building

[yar]

What are my options for heating/cooling a 120sqft building?

I would like to go with a mini split, but I've read that they are for larger areas and won't dehumidfy the air properly because they won't run long enough.

 

[Fitter30]

Motel unit called a PTAC through the wall. Comes in straight cooling, heat pump or with electric heat. Window ac mounted in the wall.