I have been running a portable AC this summer here in Florida in a two car garage sized shop. It is a combo AC, dehumidifier, heat pump. So far I like it very well. I cut a hole about the size of a dryer vent in the wall rather than use the existing window. The portable unit was a minimal investment up front, but a mini-split might have been cheaper in the long run. I don't expect to be here too many years, so I am okay with the cheaper up front cost and higher ongoing costs. In my case it might actually wind up actually being cheaper depending on how soon we move.
AC is pretty important here and I oversized it for the square footage.