Who gets the patent? The first one who markets a product ?

As for the patent issue, It's highly recommend that you talk to someone who knows the specifics of your idea and knows about the patent process, if not an actual patent lawyer. There are a lot of misconceptions about what kind of protection non-provisional and provisional patents offer. Also, you may get a patent granted but if it's not drafted well, someone could make a minor modification and not technically "infringe." A well-drafted patent by a good patent lawyer, however, can provide extremely good protection without being overly broad.

The U.S. patent and trademark office recognizes the first to invent, not the first to market. Going to market first helps in the sense that it strengthens your argument that you invented it first, but that argument can be refuted if the first person to invent has documentation of the date of their invention. That's why it's very important to keep a log of your invention, ideally from the first day you think of your idea. Write down all of your notes, keep track of receipts for materials, drawings, phone calls, names, dates, emails, etc.

Bottom line is read all you can and find a good patent lawyer!