>it needs to be certified unix.

What is that?
the only "certified" unix I know of have all true unix (BSD or SVRx ) code in it somewhere...
And so are licensed...
To write from scratch would be making yet a unix-like that can be certified "compliant" maybe but it cannot be called UNIX...
Some professor in Australia gave a course quite some time ago where you had a lot of true unix source...
This said what's wrong with the existing or linux?