First question: Do you o/o the business?
Second question: Whom do you trust with the keys to the place, the bank deposit book, and code to the cash register?
IMHO you're better off--far better off, looking for a really good cook--pay well, and then take on the sales postion yourself.
What you're after is the "little black book"---the contacts, the people. If you hire someone with a good catering sales track record, you are paying for this book, if you hire someone with no sales experience, you're paying for the information that goes into the book. The book is portable--what works for you will work for any other caterer or hotel.
The pro sales person will take the book the to highest bidder, the one who makes the book will do the same after a few years.
Am I making any sense?
Forget about binding contracts, non-competitive clauses and legal hype, it won't work. A pro sales person will never sign it--it's be like cutting off his right hand, and only a real noobie would sign it as they have nothing to loose.
You are your best sales agent.
