IANAL (I Am Not A Lawyer)
As far as I know, OC spray should be legal for you. Under the ORC (Ohio Revised Code) you are not allowed to conceal on or about your person any deadly weapon or dangerous ordnance. Deadly weapon is defined as anything capable of inflicting serious physical harm (which, in the right hands, could be a Bic pen
)...which would not seem to apply to Mace or OC spray.
However, a LOCAL ordnance might apply. For instance, if some bedwetter on Cleveland City Council passed a local law banning OC spray, it would apply to you if you are within the city of Cleveland. Any local municipality or township can enact laws regulating such things (at least until a certain court case in Cinci gets resolved).
As far as recommendations:
Spray v fog v foam: there are drawbacks and benefits of all three. Get a cannister of each and try it out, see what you like and don't like. I dislike fog- it really spreads out and, frankly, I dislike breathing the stuff. YMMV.
%OC: I think the general thought is that %OC is less important than SCU (see below). Some people even state that %OC that is too high makes it less effective than a lower %OC product. I dunno if thats true or not, but I think that delivery mechanism and SCU are the two more important considerations.
SCU: The higher the better. SCU stands for Scoville Heat Units (?) and is a rating of how hot hot-peppers are. IIRC Fox Labs has one of the highest SCU products on the market. I got nailed with Fox in academy and it royally sucked.
Also, do a search on "OC" and you'll find a ton of responses.
Mike