Many U.S. teachers begin their professional training with Arthur Murrays or Fred Astaire. Either of these franchised schools will give you free training, in exchange for something like a 1-year contract. The level of dancing is not highly competitive, but it's a start. Also, it depends on which school you go to... If you find one with a really good teacher, then you're set. Generally, Freds is a bit more into the competitive scene than Murrays, which is almost strictly social.

Since you're willing to relocate, as a serious dancer you might consider the Metronome Ballroom, which is located somewhere in the San Francisco area. I hear they have a phenomenal professional training program.

It also doesn't hurt to get a partner, since you can split the cost of coaching. Also, practicing with a partner will increase your speed of progression considerably.

I hope this helps.

Sincerely,
Jonathan Atkinson