First off as somebody who has made the transition from Wales to the USA let me assure you of one thing. Getting married to a USA citizen does not assure you of a green card or residency. People who tell you this are mistaken. After marrying my American wife it took over 3 years to finally get the green card. There is a lot of paperwork, documentation, background checking, immigration medical and interview to go through first.
Secondly if you are granted a temporary work permit, good for 1 year, after your initial application then you have the wonderful experience of entering the pilot pool and looking for a job. The pilot job market here is awash with pilots that have thousands of hours of jet time so beware of what you are getting into.
Thirdly living in the USA may or may not suit you. It is very different both in good and some not so good ways. Remember this is a land without pubs and fish and chip shops
Cymru am byth.