oracle collaboration suite (Score 1)

you can implement this scalable and redundant, it offers all services mentioned plus more. With this http://www.oracle.com/technology/products/cs/index .html you can also use the oracle database as datastore for all kinds of docs, effectively replacing fileservers. Don't forget things like backup & recovery ... I don't know how others think about this or have experiences with it but I think it worth some investigation. It has a price tag per user but with a full implementation it could be a nice price... http://homepage.mac.com/ik_zelf/oracle