Quote Originally Posted by Sterob View Post
The Solid ALi Bed will bolt directly to the frame so I guess that negates the need as well..
Not at all. The bed will offer very little stiffness if the rest of the frame isn't good enough. The frame is the foundation and like any structure, it will fail if the foundations are poor.

The key is to try and lower vibrations so triangulation and bracing should be used with this goal in mind.

I would also hold off on the Aluminium bed unless you are really sure that it will be needed because you'll probably find it's covered most of the time with a Spoil board of some kind so not to cut into it, usually MDF. An aluminum T-slot type or even a Matrix of holes type bed can become an expensive base that isn't required for most wood routers as you'll often be screwing parts down into waste material or screwing clamps etc into areas that you couldn't reach with a T-slot type aluminum bed.