Build your own (TM) Widget. Don't use TabLayoutPanel as you will have to sync the app lifecycle, the tab lifecycle.
Simply create a widget where you change the layout of the menu-items (they can be as simple as bunch of labels in a flowpanel).
To create the main layout I usually use a set of LayoutPanels (forget about docklayoutpanel, it's not good). Somewhere you place a Simplelayoupanel, call it content and you give it to the placemananger.