I'm sure there are engineers on this board that could give you all the info in concrete strength and reinforcement requirements.
Though I have been out of the business a while, we used 12 inch centers on 4 inch pours and 18 inch centers on 6 inch for our rebar spacing. Wire mesh works too but is a pain to use on smaller runs.
If it was my shop I would run wire mesh and then tie it together with #4 rebar. Then the 2nd day after the pour I would cut groves every 10 feet.
Overkill, maybe but I never had to go back and redo any of my jobs.
