In case you missed the announcement, you can now deploy SCOM 2012 R2 CU5 and use SQL 2014 as your database server platform.
The product group announcement and caveats are here: http://blogs.technet.com/b/momteam/archive/2015/02/23/opsmgr-2012-r2-now-offers-additional-support-for-sql-server.aspx