I'm late to this discussion and apologize if I'm replying incorrectly. What was the outcome of this project? I've used American Fibertek for something similar and recently purchased a 4 channel bi directional unit from Voscom (China) It arrived in three days and works great.
I successfully completed the fiber conversion with Extron Fox Tx/Rx AV. The football field already had fiber runs going from one side of the field to the other with some room for spares, so I got a local cabling subcontractor to install and test multimode fiber patch cords. I called Extron to make sure the units would handle audio without video. (They do.) We decided not to buy the Voscom because they have no US distributor, and warranty service would be difficult if needed.
