Just added a floor in my (32x32) garage.

Over the dried clean concrete place a moisture barrier as recommended by most if not all floor manufactures.

Lay 1 or 2 (your pref) layers of the foam cork flooring used in condos to reduce noise and vibration.

Cover with the floor of your choice.
I agree the real wood could be costly and require alot of care. I went with the snap together laminate- looks and feels GREAT!

Good Luck, let me know if you want some pics.