I would say bin the FAA training and switch straight to JAA modular. You can stay right there in Florida and do the hour building on your FAA PPL to get to 150 hours. You need not convert it to a JAA PPL, as any ICAO PPL is acceptable to commence JAA ATPL theory. The Jeppeson manuals can be used as a costly doorstop because any school you enroll with will probably have different books or if they use the Jeps, may not give you much price reduction for having your own set even if they are the correct revision. Flog them on eBay and cut your losses since Bristol GS and Oxford DL don't use them (OAA has their own books, not sure about BGS).
Finishing an FAA CPL/IR makes no sense at all when you can do JAA CPL in the US and do a JAA IR and MCC back in Europe. Getting an FAA CPL/ME/IR then a JAA conversion just sets you back an extra £10-15K and takes an extra 9 months.
Thank you so much for your response. This clarifies things alot.
I will talk to the school manager first thing tomorrow and ask if I can spend the $4500 I have left in my school account to build hours on my own. Don't think they'll like it much at all, but worst case scenario I could always just have it done at another school here. Hopefully I can accumulate the 90 more hours I need before christmas, so I won't have to come back here after spending christmas and NYE in norway. Shouldn't be much of a problem getting it done in 2 months (my ticket back home is 18. december) if they are willing to co-operate, after all there is definitely no shortage of C172 nav II's here.
I'll probably go on some long ass X-countries with my roommate for the hourbuilding if it turns out I'm not banned to ever set foot at school premises tomorrow!