How do I get a hairpiece?

I'm new to this whole thing and was wondering if someone could just guide me through the process of getting one. Where to order from, how to go about doing it, how long will it take etc etc, things like that. I was thinking about using quiff co. but people have told me I could achieve the same results at a much cheaper price so any suggestions are welcome. Also, for reasons unknown, I'm basically losing all the hair on my head so is it possible to obtain a piece that will cover the eternity of the scalp?

Thanks in advance