Orbi RBR50 (router) with RBS20 (Satellite)

Dear all,

I have currently a Orbi system with the RBR20 and 3 x RBS20, unfortunately the walls are thick concrete with 

a lot of iron inside the high rise building. I am now thinking to upgrade my systesm. Is it possible to use the 

RBR50 (router) with the RBS20 (satelites) I have already?

My idea would be to have a mix of my existing RBS20 (satelites) with a RBR50 (Router) and an additional RBS50 (satelite)

One other question, is it possible only to by the power adapter separatly? This way I could use the RBR20 in my parents

house back in Europe.

Thanks,

Michael