No problem. I don't see any issues with that Maertron cable. The only issue I can think of would be wether or not you either will or will not need a powered tee fitting on the backbone. I would bet that you would not. The 12v prob comes from the "key on" ignition feed--through the Maertron cable...As long as the network is put together with term resisters are the ends, you should be good.
Did you just call the dealer you linked above? They seem to have an excellent tutorial and would prob know exctly what you need. Seatalk NG has been around a while. It's all the same from Raymarine plotter to Raymarine plotter. See below..
http://www.blueheronmarine.com/How-D...0-Display-6322
Maybe someone else will chime in to confirm....