Thank you for answering.
I was hoping on using Cat5E-STP and piggy backing the video on pins 3 and 6 which are not used for the RS485 communications. . . if that is even possible?
I have not decided on a final camera yet, and for the moment am using a BOSCAM HD19 as I had one on hand, but I know it is ill-suited to the job.
The idea for the OSD came from this thread:
viewtopic.php?f=4&t=1533&hilit=osd
He used HobbyTronics Max7456 breakout for the OSD and a SparkFun triple axis magnetometer (I am trying to copy this exactly) for direction and I am assuming is compensated just from seeing what he has already worked out.
The motor drivers have been switched out already due to supply issues with the manufacturer, but I'll report back on the replacements when I get and test them.
I am new to the Arduino and programming in general so this will be an "adventure", but I really want to see this work.
I hindsight too both of my posts on this project are in the wrong sections, and should be under the newbie section as my background is mechanical systems and not electronics.