This is a very cool project and a bad business idea. I cut my own hair with a Wahl trimmer. Have you gotten liability insurance quotes for this yet?

I am not trying to be a buzzkill but you are going to knick ears, pull out small chunks of hair, and other minor trauma on customers if you try this. You want to have that liability insured and if not you might put yourself in personal financial or legal jeopardy, regardless of legal waivers (IANAL).