Thanks. I have actually looked at the PID library and it seemed too complex for what I am trying to do, especially with trying to tie in a bunch of motors. It could be that I am just not understanding it fully. if someone is willing to help me figure out how to incorporate it, I would be extremely grateful.
As for the loop suggestion. That is the idea. New, incoming serial commands get loaded into the array. A loop pulls the commands out of the array and updates the motors. If no new commands were loaded, it just refreshes the motors to the last position they were in the array (in case they had moved somehow.) That generically holds the position. Upon first initialization, I load all the default positions into the array for neutral. And the head will move into a nuetral state on the next update.
So, I am technically only commanding a single motor at a time but instead of directly moving the motor I load the command into an array, and a timer triggers the update routine and refreshes the motors.