Yes we've used MOM as well and it has many tools and methods but really think he would be happy with Insight.

Surprised any shop that size though hasn't alredy installed it. Our HP/Compaq rep have always let us know about it and offered assistance with it when required for years at my last job.

In fact MOM relies on the underlying Insight Agents to be able to monitor all the low level details of the HP Server.
It can do a lot of WMI stuff on it's own, but then you're really missing out on details since the Insight Agents were specifically written to gather the details on the system much more so than WMI alone, as many of these other packages would do as well.