JBeckman, you might be getting in over your head. First off a rule of thumb for bids is $10-$20 per linear foot for hoods and $40 - $60 per fan. You can also charge for filters $5 to $8 per or not do them or include them as part of the job price. When lawsuits are flying the so-called corporate veil is transparent - the real advantage of S corp over sole proprietorship is the tax advantage. Ask your accountant, bookkeeper, lawyer. The best soap is something with a lot of sodium hydroxide. Whatever works for your job. Also bring scrapers to get the heavy grease. The best advice, if you are serious, get trained by someone who knows the ropes. You'll have to pay but it's worth it.