I've been told that high-end TrippLite suppressors have/had a meaningful indicator. A quick Google search didn't confirm that. If they do, plug your CPU and monitor into a UPS and all other equipment into a TrippLite suppressor,

TrippLite also makes UPS'es. Again, I can't determine from their web site that they report protection status.

Also, if you are not familiar with MOV's look up "metal oxide varistors" in Wikipedia.