Well, the Kona is RGB out for monitoring and SDI out for everything else. There is a way to get composite out of it but why? The HD/SD RGB coming out of the BOB is fantastic for monitoring to a compatible monitor or Plasma/LCD etc. If your devices (the switcher?) will not accept either RGB or SDI then it's obvious you'll need converters to do so and they can tally up the costs really fast. There are component switchers (for feeding monitors etc) that won't break the bank. Now, what about audio? It's ONLY AES in/out except for the phono conectors on the BOB for monitoring only though I recommend listening to the AES so you absolutely know what your are sending for delivery.
Don't hesitate to keep asking. We all either want help here are or willing to offer it.
You will want to add an AJA Io LA for all your Analog I/O to the box.
No S-Video in or out of the Kona 3. For Composite you would need to keep switching the Component output to Composite.
The Io LA is a perfect complement to the Kona 3 and you can easily switch your outputs from Final Cut Pro from the Kona to the Io. We have one Io LA that moves around from system to system depending on who needs the analog connectivity and it works very well.