You will be able to do the JAA PPL with Anglo, then do 100hrs hour building once you receive PPL from the CAA. You will also need an FAA PPL to fly solo in the states but this should not take the 90 days as mentioned. The only delay you will have between gaining PPL and hour building is how long it takes the CAA to issue you with your PPL and how long it takes them to forward info on to the FAA so they can issue you with an FAA PPL.
The FAA are very efficient and once all paperwork is passed onto them all it takes is a day trip to any of their many offices throughout the states and you will be issued with a temporary 90 day FAA PPL in which you can build your hours while your licence is been processed.
As for Anglo American Aviation there are a few threads on this site which will give you the pros and cons if you do the search. I did my PPL there and have no regrets, i am going back there in 2 weeks to do a bit of hour building. Amazing place fly, trip to Vegas is in order however will be pretty hot crossing through the desert at this time of year so will be keeping a/c at 10,000ft
