Every electronic equipment like the amp comes with a maximum power consumption rating. This with a provision for enough headroom can be used very safely to determine the capacity of the source of power. In any case this is always done for every usage, from the wall sources or the power substations, just the scale of power-capacity varies.
There is absolutely no limiting factor in using, for example, a good quality servo stabilizer to provide power to an amp, provided the capacity is large enough.
I have just got installed a servo stabilizer with 3 KVA capacity while my total requirement is perhaps just over 1 KVA. The well-known and good quality ones are Krykard, Vertex and Aplab. In addition, there may be other good ones locally available (like dinyaar mentions that he uses an Argo servo stabilizer available in Bombay). Mine is from Krykard with RFI/Filter and surge suppressor, costing around 13K inclusive of all taxes and shipping. It's a heavy unit, weighing nearly 30 kg. Krykard has offices in Kochi and Tiruvananthapuram. I am sure the other brands mentioned above can also be located near where you live.
The reason I got a 3 KVA, instead of a 2 KVA (as I was initially thinking), is that in a private communication our forum member SuhasG mentioned that the price difference between a 2 KVA unit and a 3 KVA unit is usually not that high and it's always better to get a higher capacity keeping in mind any future increase of requirements.
I can tell you that not only they protect your expensive equipments, the sound quality improves because of cleaner and steadier power supply, a bit like late night sessions when the quality of power supply improves and is a good time generally to listen to music if the neighbours do not complain.
Of course, the most ideal solution would be to use an ultra isolation transformer (UIT) along with a good quality servo based stablizer, but for almost all situations (barring extremes), having a good quality servo stab is enough, I have been told. I actually have plans to get a UIT at a later stage, but have not decided on that.