ManagedBean Design Issue

The image above is the template for my website. Left and top menus will stay forever (left one will be toogleable though). Only frame(green area) will change and when user scrolls, only the green area will be scrolled, menus will stay in screen.

So, my idea is to use <ui:include src="somepage.xhtml" /> when designing the webpage templated above. My problem is every ``` sub page will have its own managedbean. Is this a good design choice? And for the main managedbean how should i call subpages? by just firing an event on menu click and replacing the current frame? What will be the scope of frame beans? RequestScoped or ViewScoped?

Please guide me, thanks