Why do this? Figuring at $15.00 a pop for a standard servo, for $60.00 you can get one that would more than handle the job. Four sevos take up a lot of space unless you have the room.
Most of the newer servos are all pretty much universal now, one of the exceptions being the older Airtronics which now come with a "Z" connector. Yes, it is possible to swap wire leads, I've done it a lot.