Arduino automated curtains

I am having a project of controlling 8 curtains using 8 servo using the arduino. Right now i have an arduino Uno R3 and an 8 ports relay board. the problem is the the curtains will be far from each other with a minimum distance of 5 m and a maximum of 20 m and each servo will have its own power supply. my question is could i pull off long wires from the relay boards to the servos, it should be 6v each and 10mA each, and how will i wire the external power supply to power the motors?

This ins't clear.. make a drawing. Show how you think to this should work