It's likely tougher over here, much more competition. To make money as an actor, not work unpaid or almost unpaid, you must belong to SAG, the union. It is really tough to join SAG for most actors, you have to work in a SAG production in a principal role, meaning you usually have to know someone that will put you in a SAG production even though you aren't SAG yet and probably don't have much experience, it's a huge favor. But if you don't have a good enough resume, even if you're SAG, you likely won't be hired for SAG productions until you get more experience, but now if you're SAG member, you can't do many of the non-union unpaid/almost unpaid work you did before, so you can't build your resume. Crazy, huh?
It is just so competitive here, so many people want to be actors, including many local kids who have been in professional acting lessons and working since they were 7, so they have a real advantage. Even getting non-paid jobs, like student films, is very competitive, many very fine actors audition.
Only 5 percent of SAG members make more than $75,000 a year from acting, middle class in LA is about $100,000 because it is so expensive (you'd have to make twice that to buy a modest home in a safe area). 2/3 of members make less than $1000 a year from acting. In other words, most actors don't make money from acting. They used to be able to make an ok living as waiters (tips), but not anymore, the restaurant business has suffered big time due to the economy. There just aren't that many jobs with flexible hours/night time that pay more than minimum wage, and literally, a minimum wage job barely covers rent!
Anyway, you wouldn't be able to move here to work, there is no way you'd get a work visa. You'd have to be a very well known actor to get a working visa, and already hired. The only way you'd be able to work is in a cultural exchange program, but you'd have to be a university student and you wouldn't be able to work acting, it's usually work like camp counselor, hotel worker, etc. No production would hire you without a proper visa, we have a zillion+ actors, no need to hire someone who is a hassle. Even competitions (like So You Think You Can Dance) require foreign contestants to have work visas, and they won't arrange them, even for top contenders.
Lots of British and Australian (and Canadian) actors work on US TV, and in movies, after successful careers in their own countries. But success seems to come in portraying Americans. So work on your career in England, and work on your American accent. Most of the foreign actors here are known in their countries. Supposedly in 2008, one-third of all piloted American TV series had British people in a starring or main supporting role. If you can't make it as an actor in England, your chances here are much less.
Foreign actors playing American (big roles) on recent TV shows:
Ed Westwick - Gossip Girl
Gabrielle Anwar - Burn Notice
Sonya Wagner - Flash Forward
Joseph Fiennes - Flash Forward
Hugh Laurie - House
Matthew Rhys - Brothers & Sisters
Anthony LaPaglia - Without a Trace
Marianne Jean-Baptiste - Without a Trace
Joely Richardson - Nip/Tuck
Simon Baker - The Mentalist
Owain Yeoman - The Mentalist
Charlie Hunnam - Sons of Anarchy
Anna Friel - Pushing Daisies
Dominic West - The Wire
Idris Elba - The Wire
Natascha McElhone - Californication
Ian McShane - Deadwood
Eddie Izzard - The Riches
Minnie Driver - The Riches
Jason Clark - Chicago Code
Jack Weber - Medium
Yvonne Strahovski - Chuck
Louise Lombard - CSI: Crime Scene Investigation
Damian Lewis - Life
Jason O'Mara - Life on Mars
Johnny Lee Miller - Eli Stone
Alex O'Loughlin - Hawaii Five-O
Rose Byrne - Damages