I'm sure most U.K. universities will accept a 4-year degree from the US, there are many international students study there for their masters.

I know you and I are both in the same situation in terms of moving to the UK. I've been doing a lot of researching in terms of the quality of life in England and it seems like it's not all that it is hyped up to be, unfortunately. Housing is ridiculously expensive (London is the biggest and most expensive European city to live in, and one of the top 10 most expensive in the world), houses are cramped, and most people don't have much disposable income because their wages are heavily taxed.

It's a big stereotype, but it seems like the attitude there on life is to learn to live with very little. Whereas in the US, people have an aspiration to work hard and increase their standard of living (big house + nice cars) + lots of disposable income.