Hello, and welcome to the board.
I don't have a model release that I could give you, but there are two things that I could recommend:
1) Do a search for some boilerplate model releases. Here's an example of one I found with a quick search on Google:
http://www.dvcontent.com/release.htm.
2) The best advice, though, would be to find a lawyer or legal equivalent who can draft a custom model release for you. This would probably be only a one time cost and would definitely be a wise investment for your growing business.
Best of luck to you
