AVR voltage regulator - what to look for

My AC main voltage seems to have crept up quite a bit. We used to get ~225V AC a few years back, and now it is around 240V-245V AC.:scratch1:

Given the situation, I am thinking of installing an AVR (Automatic Voltage Regulator).

There are various types - which ones are good for audio?

I have posted on the solid state forum as I intend to run solid state gear on the AVR regulated mains. If the moderators think this thread should be part of another sub-forum, please move it there.