Metroman ,ya gotta have US citizenship or the Green Card to be hired on by any aircraft operator. But to answer your question about opportunities....there are quite a few for American citizens and Permanent Residents (green card holders).
I read a thread a couple weeks ago between an American pilot in Alaska and a South African. They were discussing the prospects for employment in Alaska for foreigners. It seems there's a serious shortage of pilots at your level in Alaska. Go back in the logs a couple weeks in the North American section and you will get the thread.
Good luck