Restricting access by usergroup

[rchilders]

I want to set up a board environment where I have 4 usergroups.
Each user group will have 3 or 4 sub groups.
Each user goups can only see their forums and group members.
Each user group has it's own stylesheet.
Can I pass usernames and passwords to vbulletin to speed up login for each group?

Is there a plugin or several plugins to help with this?