[support] Log in according to user responsibility

[Roger]

Using Drupal 6.19

We have a generic member's login for group members with password and 
user based on a current newsletter publication but this does not 
facilitate different pages depending on user.

In our system certain users each have a role/responsibility.

6 coordinators who input calendar events for their particular State or 
Region.
6 coordinators update page displays for their State or Territory
12 reviewers who each review one of the above and approve or not, but do 
not have editing permissions.
None of the above have admin permission.
Permissions are tight and only for the explicit role.

It is intended that the menus for each will provide only: Create 
content, edit, review, approve, send back, unpublish as appropriate for 
the role.

The coordinator can see the page he/she is working on, but must be able 
to see the 'as if live' page before submitting it.
Primarily because the cck editor does not present good representation of 
a live preview.
The reviewer receives notification, views the completed page 'as if' it 
were live and approves/publishes or sends back for editing.

Each of the above has their own user name and password. A reviewer for a 
particular region would use for example, 'reviewer-victoria' as the user 
name
'some_password' as the password

Question: How can I set up a log in for each role so that it presents 
the appropriate log in page and menu, specific to that user login?
The menu system I think I can do ok but I cannot find how to present the 
correct login page per user.

Thanks in advance
Roger