I have a mini split in my garage. Bought it on Ebay. You have lot of choices in one spot and it will come right to your door. BTW the mini spit is so quite I can't tell if it is on or off. I really like the system.
You should check out the polyurea coatings. It is a spray on product that's pretty tuff. It's used for all types of industrial costing and spray on truck bed liners. You could also acid wash and stain the floor as well.