I would urge caution about taking FAA ratings and converting them to JAA due to the extra time and expense. You'll need to do some detailed budget planning for both routes; JAA in US/EU and FAA in US to JAA conversion in EU.
Step 1 in conversion is to do JAA theory, which will take about six months. Some people do it by Distance Learning and knock it out a bit quicker but I think most people need six months. That's how long it takes if you do it in a full time classroom course also.
It could then take several more months for CPL and IR conversion. This will depend greatly on the school you choose and the weather, which tends too be poor during the winter in the UK, but maybe better in southern Europe.
The conversion method will cost you a minimum of 8 extra months of meals and accommodation and probably £10K to £15K in training costs. It also delays the date you can start a job and earn wages. The delay actually might not be so bad the way the economy is rumbling right now though.
Also remember if you do FAA then JAA conversion, you can do the JAA CPL conversion course in the USA and it should be less expensive there.