In truth, I went the other direction - from the US to Europe. But I just happen to be in the finance business (MBA, CPA) and have done some hiring, both in Europe and in the US.

The trouble with the "evaluation company" is that they can tell you anything they like about the equivalence of your experience with US degrees or certifications. It's ultimately up to the employer whether or not they "buy" it - and honestly, if there is a US MBA or any candidate with a US degree in finance or accounting up for the job, it's a whole lot easier (not to mention cheaper) to hire someone locally. (It costs an employer over $1000 to petition for an H1B candidate.)

I don't know what kind of work you're doing now, but you may want to consider finding a job at home (the UK, I take it) with a large, preferably international company where you might get a shot at a transfer to the US after a couple of years. It helps if you can manage to get a job with periodic travel to the US - meetings, training, just about anything - because that gets you in front of the hiring managers over there. If they are impressed with your background and experience, it can make life much easier when it comes to transferring.
Cheers,
Bev