One way to help distribute the workload in a ConfigMgr infrastructure is to move the customer facing roles off of the site server. Build the site server with enough horsepower to handle SQL and SQL Server Reporting Services. Keep the Site Database, Reporting Services Point, Endpoint Protection Point roles on the site server. Plan for enough storage on the site server to store the ConfigMgr backup locally, but then use your enterprise backup software to backup the ConfigMgr Backup folder.
You can move roles like the Management Point and Distribution Points on to other servers. Since the sender is now used to distribute content to distribution points, it is OK to locate a distribution point remotely.
For more of my ConfigMgr hints and tips, please visit http://sysmgtunderground.wordpress.com/ or see the Microsoft TechNet forums: http://social.technet.microsoft.com/Forums/en-US/user/threads?user=Bruce%20Hethcote