Thanks for all your answers!
Komplete 8 Ultimate, Sample logic, Samproject, Vir2 seems good but I haven't enough money for it!
For the money I think I need a "beginner VI's Library" (I'm not professional). It's why I think of K8 (not Ultimate), MachFive 3 or IEP appear to be the best choice for me!
Do you know if in this video, they use "Structure" or "Structure East west symphonic edition"?
http://www.youtube.com/watch?v=x9j0niiQ7no
Because for me, the orchestral instruments are just I need for the moment.