Opengl design...multiple viewports or just a single view port

Hi

I am in the process of building a tool to view levels graphically and meta data associated with that level, to keep things simple I will describe a very simple screen layout.

Menu at the top
2d Meta panel on the left
3d scene viewer for the remainder of the scene

This is pretty simple to draw in a single view port, the 2d panel and menu would over lap and hide the 3d scene when they are drawn and menu open clicks would generate a drop down menu which would again over lap the 3d scene.

If I wanted to have multiple view ports (ie displaying multiple 3d scenes on the same screen) it would make sense to have multiple view ports so each view port doesn’t interfere with the other. If you do this the 2d panel and menu might as well be in their own view port too. The problem with this is the menu drop down would fall out side its designated view port space when it opens and wouldn’t be able to overlap the 3d scene.

I might be misunderstanding view ports (as I haven’t gone down that road yet) but, is there a clever way to handle the menu problem so I can have multiple view ports? Or should I stick with a single view port and force everything to work there?

Any help here would be great