Most (if not all) modern household equipement works fine with very wide supply voltage range. The only one of which I can think is a light bulb which will flicker.
Other devices that dislike fluctuating voltage are vacuum tube radios/amplifier/whatever.
So I would ask, why You need such a regulator?
AC/AC voltage inverter (like the one used to control AC motors) is a sulution, unfortunately it's not cheap, and many of them are made to regulate three-phase motors. Also You need to see, if the inverter has an transformer, otherwise it would be unable to regulate until the input voltage is higher than desired output voltage.
The other important issue is the shape of output waveform, it should be true sine, not so called 'modified sine wave'.