I buy bulk servo wire when it comes up on sale at Hobby People. If I need a lead that is two feet long I cut two feet of wire then cut the servo wire in half and solder the wire between the servo lead wire. You can stagger the soldered area or just leave the ends all flush. I use heat shrink tube over the solder splice so there is never any shorting. Once soldered it doesn't corrode. If you need a photo I can take one for you.
Gene