I've yet to see a cable that has protection against fluctuations !
If you have £60 to spend - buy a UPS - like the 1200VA one from
Ebuyer (Quickfind: 64159) which will power your gear through short power interruptions, and protect against spikes and surges. What's more, you'll get £13 change from your £60
The cheaper "Surge arrester" cables has a device inside that blows like a fuse at the first sign of a surge, and after that, all you have is an ordinary power strip.
If you buy the Ebuyer unit, it has IEC (kettle type) sockets on the back for power output, and you will need cables (Quickfind: 40660).