I am planning my first hardware setup, and someday when I passed by an acrilic shop, I saw this frosted acrilic. Has anyone tried to rear-project on this kind of surface?

There are better surfaces for rear projection, but it will work and its not bad.  Othrer more expensive options are drafting film/vellum, Lee filters difusion gel and Rosco Grey which is what is used for rear projection fastfold screens.