CNS server or Nagios for new deployment?

Trying to tell if CNS server is being depreciated or not...  I have a brand new, fairly small ePMP deployment (3 APs and ~30 SMs) that I need internal monitoring and alerting on.  We are using cnMaestro but it does not have alerting yet.  Do I deploy a small PC and load CNS on it or go the Nagios route on a Raspberry Pi for internal monitoring before cnMaestro is more mature?