The instructing has been done above I think. For an FAA CPL you need 250 hours and can go straight to CFI then. Remember to get a paid job you will need a J1 visa (if you are not a US green card holder or citizen).
Another way to build hours and experience (can be done on a PPL if no payment) is to fly glider tugs or para drop planes, but both of these will also present experience problems. You will need 100 hours P1 and need to be a glider pilot to tug them. For paras a lot of clubs use quite exotic aircraft - meaning turbo prop. Don't think with minimum hours and a PPL you are likely to be let loose on a Cesna Caravan or such like. A lot of more "qualified" pilots would sell their grandmother to get TP experience.
Once you have your PPL you can get some cheaper hour with no equity groups or short term lease (probably 20 hours a week for 2 or 3 or 4 weeks) all worth looking at to build P1 at an acceptable cost.
It aint going to be easy and it aint going to be cheap. Also remember the JAA ATP written exams take a long time to do. Allow about a year distance learning and 6 months full time - oh and about £3000 very much minimum.
All the very best to you.