In what way is the existing NLB template not working for you? If you're receiving the error message: "Invalid namespace." from the "NLB Cluster node status" it's likely that you have not configured the correct target machine name in WQL script.
From the documentation:
Note: Before using this monitor, you should set the correct NLB node name. Replace NLB_node with the NLB node name on which you applied this template in the WQL query section.