Professional epoxy. Not DIY...professional. A high-end epoxy will do everything you want and look cool while doing it.

Converted garages are tough. The slab concrete is DIFFERENT than the house slab. There is NOT vapour barrier underneath. And the darn things are sloped towards the door (so that liquids will run out when you open the door).

These two things put together make it a HUGE challenge to get regular flooring into a garage. Epoxy (professional grade stuff) will get it done.

It won't be cheap. A "regular" epoxy can start at $5/sf. The really COOL looking ones start at $10/sf...you get the idea. The price tag should include LABOR and materials.

Other flooring options require huge amount of prep for the slab. If you want to put a car back over it, you need to LEAVE the slope...and have something that will accept rubber tires sitting on it. Epoxy fits the bill. Have fun. These are some pretty cool floors.