Thanks! I pieced it together like so:
First I used a paddle bit (5/8 if I recall) to drill the hole in front of each seat.
Then I covered with this...
Keyhole Escutcheon: http://www.signaturehardware.com/product19851
Then, from the backside, I inserted these into each hole:
I used a chisel to slice a little of the sides so it would fit snugly into the circular hole.
From there I just used USB cables (also from monoprice) to connect to the usb outlets that I installed on the bartender's side.