Some of the protection devices designed mainly for use with computers (but also other electronic equipment) have practically proven their usefulness against surges, overvoltages and brownouts.

I can suggest
http://www.apc.com/products/family/index.cfm?id=67 (go for the 1200VA model)
or the simpler, but less capable
http://www.apc.com/products/family/index.cfm?id=176
these are relatively unexpensive.

M kit : G08 502 557 507 2xDSP5k