I am unable to find current information.

Well you will need to know that, if not from the data sheet then from measuring it. It is also best to measure it under full load. Then multiply up by 23 to get the total load.

At a conservative guess of 200mA per servo then you have a total current of 4.6A which is quite a lot. For 5V this is 23 Watts.

So for mobile then a lead acid battery might be good, you could get the 6v motorcycle ones.

For fixed then you are looking to convert / use a PC's PSU.