Submission, moderation and approval setup : per page editor-role and per node approval-role

Hi,

I'm working on a multi-language websitefor a non-profit organisation. They require a specific submission-approval structure.

The organisation has several physical sites (per region) and every site should have his own page (just one).
One person per region/page would be editor and one would approve the page. But really just that specific page and no other.

I already tried several possibilities but without a satisfying result.

I installed the simple access module. This almost did the trick, except that when the user changes the content of the page and the content is not approved yet, the page is inaccessible. Access to the page is denied for anonymous users and the editor. When the post is approved, the page becomes accessible again.

I created a revision, I assumed that maybe the former published and approved revision would stay on the site, till the new version is approved. But this is apparently not the case.

Does anyone now how to accomplish my goal ?
One user editing one page. And one person approving just that new version of the page. While other content is read-only ?

thanx