I've had the same issue with a different type of business - we could easily break stuff, cause a trip/fall hazard, or drop things on people. (Except for a few tiny breakages, we never did.) I went from a sole proprietorship (young guy, no assets to sue for, time to recover) to an S-corp, then to an LLC when that became available.
I'm not sure an S-corp provides any better protection than an LLC, which is a lot less trouble and cost. Lawyers, please chime in.
I do think you should try to establish business credit separate from your own, ASAP.