My latest OpenSource Project (https://sourceforge.net/projects/wmimonitor/) is a simple WMI Provider written in C# (.NET 3.5 SP1 is required) to list the Serial Number and Model name of the attached Monitor(s).
It creates a new WMI Class "Win32_MonitorDetail" in the WMI Namespace root\cimv2:
wmic:root\cli>path win32_MonitorDetailsModel MonitorID PnPID SerialNumberDELL 2405FPW DELA010 5&13b1d479&0&10000084&01&00 M67545xxxxxx
You can extend the SMS/SCCM Hardware Inventory to include this class in the inventory.
Check out the source code (150 Lines) at : http://wmimonitor.svn.sourceforge.net/viewvc/wmimonitor/DisplayInfoWMIProvider/WMIProvider/WMIProvider.cs?view=markup