Gizmodo does something like this but with all content. Every post has tags and you can filter the stream by excluding certain tags (or only looking at certain tags). It's very nice. Maybe that could be done as a long term solution for all future problems like this.

Nagios is probably the best free option, although configuration can be pretty complicated. I like AppFirst, it does most of the stuff you want out of the box, and you can use any Nagios plugin to add specific functionality for whatever else you want.