If it is a sunless Tanning salon shouldn't tanning be your main offering?
Depends on whether you think this is a good product - lots of people get bored after a while and some salons offering this have a money back guarantee.
Do you know much about the workouts? How many machines you thinking of having?
I have 2 shops with 2 machines in each and both are doing well with men and women seeing positive results. My advice would be to do it but keep in mind that as soon as you do it other shops in your direct area will jump on the bandwaggon so get a good reputation quickly to keep your clients.