SBS2000 with Firewall (Sonicwall)

I have installed and been running MS-SBS2000 for a year now. I am planning to install sonicwall firewall to be more secure. Does anybody know if there is any white paper of which components of MS SBS2000 can be disabled.

I have configured to makethe SONICWALL working.
But I can’t seem to make it work without disabling some of the SBS features..

Thanks,