Hi there,
There's certainly going to be many potential solutions to what you're asking about. The correct answer for *you* will depend on your organization, your budget, and your familiarity with other technologies.
If you're looking for a good way to monitor your devices and be alerted when something goes awry, might I suggest Nagios (www.nagios.org).
Nagios is a fairly powerful, and highly customizable linux based monitoring tool that can do a wide variety of SNMP based monitoring. It has a nice web interface, and can be configured to send emails to different people/groups, based on the time of day. Best of all, it's free!
I currently use Nagios to monitor the HSRP status and fan/temp status of my switches,and the failover status of my firewalls. I found a file on the Nagios website that included some SNMP perl scripts that polled for that information. It's worked great, and even alerted me when an firewall failover event occurred.
Like I said earlier, the solution for you is going to depend on a lot of different things, but Nagios is certainly capable of monitoring and alerting on exactly the items you mentioned. It might be worth a shot.
Hope that helps!
--Brandon
