I want to be able to sync my 2 XF305's and not sure what cable I need to do this. I did not know there were so many BNC cables and do not want to order the wrong one.

Anyone have any information on this?

Any 50 or 75 ohm coaxial cable with BNC connectors should work. It's just transmitting TC, so HD-SDI rated cables probably aren't required, especially if the cameras aren't far apart.