ABD
The FAA system only has CPL's and ATPL's, there is no such thing as a "Frozen ATPL". With 1200 hours you do not satisfy the requirements for the ATPL and would therefore only be allowed to obtain a CPL.
I believe that you would then be required to add your "ratings" on to the basic CPL, these would include the Multi Rating, Instrument Rating and even the A320.
Check out Flying or Pilot magazine for the CPL schools and check out the back of Flight for at least one school that offers type ratings for people with experience on the aircraft.
Finally, you have to ask yourself is it worth it, what sort of aircraft will you end up flying with 1200 hours? Would you be better off staying in Europe? Why do you think that the employment situation is any better in the USA?
Good Luck.
Mutt