[josepostiga]

Thats I thinking about getting only via REST and mybe only cache requests by some identificator. Anyway, any help or advices very helpful!

That might work well. I don't think you'll have any problem with using only REST calls. Also, you might be able to limit the number of records to process for each request. Like a limit parameter to avoid too much information being requested on a single call. That and a smart use of cache would be an interesting solution.