If you use Google App for Email then you can download GoogleSync to sync calendars and Contacts to the blackberry Device. Works very well. I use it all the time.
If you dont use a Google App account but do have a google email account and some of other employees have it aswell, just install the app and have it sync the contact/calendars to that account.
Also look into hosting a Opensource Funambol server. You can get more details over at Funambol Open Source Mobile Cloud Sync and Push Email
to try out the service just register for an account over at http://my.funambol.com/
I dont know what's your budget like but if you can do have a look at Zimbra.
To sync files and all, you can use sugarsync. The free account gives you 2GB of space and allows you to sync 3 devices. 2 Pc's/Mac and 1 Mobile Device. It saves your files in the count and allows you to access them from anywhere. Has a nice native client for BB.
Let me know if any of these help your cause.