Have you thought about going with an acid stain topped with clear top coat? Several garages in my area have this and if you use 2+ stain colors it can look incredible. I did a 2 color stain on my BBQ island (poured concrete top) and it looks like worn leather. I'm definitely going that route in my 3 car garage. Cheap and easier than paint.
Edit- here's a pic of my BBQ island
