Chama,
Near Miami sounds like...Hialeah? Welcome to the forum. You've stumbled on a bunch of guys and gals that have found an enjoyable hobby in motorized bicycles. Keep us informed of what you choose to build and feel free to ask if you have questions or problems with your first bike. I was born and raised in Miami, good town, lots of great memories of growing up there. Lots of places to ride too. Old Cutler Road would be fun. What's left of it after Andrew. Coaster brake and a good front one will be sufficient. have fun, ride safe and keep in touch.
Tom