Looking at the data sheet the 557s draw 1200 as per the 559s but the G56s seem to be 325 ish.

So allowing for confusing definitions it would appear to be quite different in build and normal UPS might suffice for a G56?

Otherwise a plug protector may be the only option.
I see these vary though quite a lot, and a higher quality surge protector block seems to offer greater protection, but these are frowned upon by some as degrading sound?