How to size your SCOM environment
Additional items to consider sizing a SCOM environment
# of Unix Servers
Network monitoring
Application Performance Monitoring (APM)
URL monitoring (transactional and availability)
DB Data retention requirements
Resources
The SCOM Sizing calculator XLS on TechNet to determine capacity and storage needs (2012 and 2016) https://download.microsoft.com/download/C/A/6/CA60425C-950B-456E-986C-C5F2FCD5668D/System%20Center%202012%20Operations%20Manager%20Sizing%20Helper%20Tool%20v1.xls
2016 Quick Start guide https://blogs.technet.microsoft.com/kevinholman/2016/10/22/opsmgr-2016-quickstart-deployment-guide/
How To upgrade to UR1 https://blogs.technet.microsoft.com/kevinholman/2016/10/22/ur1-for-scom-2016-step-by-step/
Here is the 2016 System Center SQL matrix (SCOM)
System Center 2012 R2 Matrix (SCOM)
https://technet.microsoft.com/en-us/library/dn281933.aspx
Not quite related, but incase SCCM is to be upgraded (SCCM does show support for all SQL versions)