I don't quite understand the comment "five years for self-improver." I have known people do the whole modular course in 9 months - ok they were clever but it can be done.
With an FAA licence you still have to do the JAA ATPL exams.
I am a JAA CPL/IR flying business jets and I am looking at gaining my FAA ticket purely because I have been offered work on an N reg flying private stuff.
I would suggest going modular in the UK with someone well tried and tested - eg Bristol. You don't need to look at instructing if you go down this route - airlines are taking modular folks aswell - especially with a TR.