Try TurnkeyFX. Low commissions, good execution, high volume, low spreads, excellent customer service, based in London but unregulated so they can accept US customers, you can speak to live people on the phone, they response quickly to emails, and are highly rated on forex peace army. @nick3232
mentioned finpro. I was also considering finpro until I learned they use TurnkeyFX's trading servers, and you pay more in commissions to Finpro, so I decided to cut out the middle man and go with Turnkey.