Sorry to rain on your parade, but getting a green card is extremely hard to do.
Working for a USA comapny over there won't get you a green card either, just an extended stay, I know been there done that.
There is only one guy I know who managed to get a green card. His wife was a nurse and went to work over there. That was a skill they really needed so a certain few got residency then a green card.
Just popping over there to live just is not going to happen. Expect to jump through many hoops and prepare to fall at the final hurdle.
To put it in perspective, there is an immigration green card lottery. It is closed and has been for a long time to member of the UK because there are too many of us out there.
BTW what is so appealing about the USA? I hope you are not looking at it through rose tinted specs.