Sally's training is fine. Work out your budget for how much you want to spend on equipment and like other posters have said, dont buy the equipment thru Sally's get it direct with Earlex. You do get what you pay for but it's a good starter kit. When you've built up a good tanning clientel then go for something better (cut down on the overspray). Solutions are a matter of preference. Most people have heard of St. Tropez and Fake Bake but thats about it. So you can use different ones and so you should. No one solution suits everyone. Try as many sample sizes as you can and evaluate them on the same people for things like longevity, fading and colouration. There's no doubt the better the equipment the better the end result, we've all seen some really dodgy orange streaky tans out there - just make sure you're not the one spraying them!
HTH
HTH