Hi Six-sixty,
I'll also be interested in recommendations for conversion schools here in the UK.
There are many schools in the USA who have good recommendations, the best idea is to contact the schools you are interested in and ask for contact details of past students who have been on courses that you are interested in.
Also, don't limit yourself to the FAA route as some people also recommend the Canadian licence (which is also ICAO) and then conversion to JAA.
At the moment I have the FAA CPL/IR SE ME and am currently going through the ATPL examinations.
All the best,
Charlie Zulu.