Your info on ERA machines is correct, there may be up to 6 212's and 6 412's operating this year for FAASA, as well as up to 5 212's from Abu Dhabi Aviation. The restriction on EU citizenship does not apply to fly these A/C, however you have to be profficient in spanish to operate in fire-fighting duties: FAASA does not operate with copilot/translators as did other spanish companies in the past.
Apart from the 3 companies mentioned on the previous post, you can google Coyotair, Sky Helicópteros, Hispánica de Aviación (HASA).