Speaking from the standpoint of protecting your equipment in my humble opinion.
If you can swing it put in a whole house suppressor off your panel. My panel is full unfortunately and is on my list of things to do
For my subs I am using the in-wall surge suppressor. Leviton 5280-IG has an isolated ground as well. Making sure you have grounded outlets is always important but, keep in mind given the interconnectivity of AV systems now you may need to also filter your phone/sat/cable as entry points.
I would agree that unless you got a commerical type UPS most residential UPS would not be suitable for an amplifier. Most residential UPS only perform basic power filtering and do not do any type of regeneration of the signal. For those that regenerate the AC signal and run off the battery you would need a larger UPS to handle the load off what an Amp may push.
I have a Panamax 5300 but, I also have some expensive equipment sitting behind it. Also put in perspective how much your gear your protecting is worth vs. how your protect your equipment because, really all your doing is buying insurance that your gear will not take a power hit.
-R
