I work for clients in the States, but I remember, even after Andrew and I got married and I got an extension on my passport, it was with the condition that I couldn't work in the UK, or receive benefits from the UK. Once I got the spouse visa to stay indefinitely, I was allowed to work here. I'm not sure about this, but I suspect you won't be allowed to work here unless you have a job lined up with a company located here before you move.