Wiping process before selling

I've been offered a decent price on my note 3 and due to upgrading to the note 5 in October I'm interested.

I want to encrypt before wiping but had some questions.

If i encrypt then do a factory reset, then input his sim in and start it up, will it then ask for the encryption key before he can use it? Or does wiping it also remove the request for a key while still keeping the original data scrambled?

Also something i can't remember from before. When i have done the reset, does it give the option to turn off ready for the first boot being when his sim is in? Or does it automatically restart so i have to allow it to boot then tell it i dont want to log in my details?

Thanks guys