Hmmm, perhaps user quotas?
So I can taylor home size on a per user basis as my power users would need more space than my standard users.
You can create template / prototype users one for each one you want a specific quota for and then use edquota -p <prototype user> <real user> and the real user will get the same quota that the prototype user has. You might need additional options like which filesystem .. I haven't used this in forever.
Barry