I was wondering if i could buy all of the Scuba Diving equipment for my own use? Do you need a permit? etc?

Yep, you could actually. You could buy just about anything to do with scuba other than a rebreather rig. The kicker is, to use any of it, you need a C card to fill a tank. All those thousands of dollars you spent on gear is pretty pointless unless you can use it with a 10 dollar air fill. No shop will fill a tank without knowing you are a certified diver. The profit simply isn’t worth the liability.That simple and a very good control measure. It’s worked for years. Greed in this case works well. It costs more to deal with litigation than to skip a C card check.