I had a good think about this and decided on industrial grade carpet, laid with underlay. I thought about spills, but decided that since in however many years I'd been doing this I'd never made a mess on the floor yet, I wasn't about to start to considering I would now have a dedicated wet area. I have a couple of bar stools which I'll rest my butt on occasionly (if my son's aren't perched on them)
I also use Anti-Fatigue mats (from Costco) over a concrete floor.
You could also consider rubber matting as used in horse boxes or horses' stables. They are slightly springy (to protect valuable horses' legs), non slip, chemically resistant and easy to clean.
Only snag is that I don't know where you would buy them from. Horse box dealers?