Best way for separated forums?
 

I've no clear idea on what is the best way to have 3 different forums for different users and if it's possible 3 different shoutboxes.

Something like:
--
forum1
subforums (open to all users)

forum2
subforums (open to only users 1 2 3 4 5)

forums3
subforums (open only to users 6 7 8 9)

admin forum (only mods and admin)

--

I'm looking for a easy configuration that won't have problems with future upgrades.

Thanks in advance

3 different shoutboxes, thats alot of server load....

Thanks for the advice.

Is there any problem with the separated forums too?

There is no problem, you can set the forum permissions for them ;)