ConfigMgr 2012 Query for All Site Systems

Did you ever want to create a collection with all ConfigMgr site servers? I like to create one for Endpoint Protection exceptions, but I want to to be a query so servers are automatically added. Here is the query I use:

select SMS_R_SYSTEM.ResourceID,SMS_R_SYSTEM.ResourceType,SMS_R_SYSTEM.Name,SMS_R_SYSTEM.SMSUniqueIdentifier,SMS_R_SYSTEM.ResourceDomainORWorkgroup,SMS_R_SYSTEM.Client from SMS_R_System  WHERE ResourceNames[0] IN (Select Distinct ServerName FROM SMS_SystemResourceList)