Be aware that if you either train in the USA or buy into an 'N' Reg aeroplane you will be attracting the spleen of many in the UK GA industry. They are invariably professionals who know all the ropes and also know that you do not.
Cynicism is an art best not practiced on the internet, Broomstick
Actually, if I may correct, the UK automatically validates ICAO (which includes FAA) PPLs for a G-reg, worldwide operation, but this is rare and I don't know of another ICAO state which does the same.
The USA is perhaps the closest, making a piggyback FAA PPL (based on a JAA or another PPL) easy to get. Most European states don't do this.
It's quite suprising the CAA has put in such a concession, IMHO. Technically, it's very reasonable (because the FAA PPL is no easier to get, in flying skills terms, than the JAA one, and its written material is completely adequate for the job) but it must be a thorn in the side of UK flying schools.