Couple things. Its good that you want to work and pay for your flight training that way. However, ATC is probably not the way to go. It would be very hard to pay for training while on ATC training pay and it'll take a WHILE to get there.

Basically, youre going to pay to be an ATC, to pay for education in another career...why not just pay for the education in the career you want? It just seems to me that you'll be paying more and taking longer to accomplish your goal.