CASA to FAA conversion of CPL/Multi IR wont be as cheap as you think. It will be at least 10-15k USD. For CFI and CFII add another 10k. Also ad housing, food and flights and it gets outrageously expensive.
Finding a flight school to hire you on an E3 is an unknown. Nobody knows what one is so selling it is a problem.
Probably best you chase hours at home.