Yeah, I bought that A.P. a couple of months ago when Defender had their big sale.
As far as powering the Sea Talk, that was a very simple matter. It comes with the cable, as evidenced by a cable with a red, black, and shield/ground wire in the box. I used a dedicated breaker with the A.P., and just piggy-backed the power wire to that circuit as well. On, off, whoopee..
Another thing. Raymarines drawing of the typical Seatalk system looked nothing like my idea of what I wanted this thing to do, which was, steer the boat. I saw no need to complicate this by networking in the kids video games or whatever. It looks like the unit will communicate with everything on the boat, and that's ok, I just do not need it. So "typical", On the five terminal "buss bar", or whatever they call it, put a terminating plug on each end, on the three left in the middle, connect the power cable, the control head, and the other cable running from it to the computer. Too easy.
One last thing. If after hooking it up, you can get underway and hit the auto button and the boat will maintain that course. The heading on the display will most likely be wrong until you calibrate the compass, but it will hold that course despite what it says. If it veers off sharply after hitting the auto button, reverse the motor wires running from the wheel to the computer. That one stumped me for a minute, but after reversing the wires, all systems go.
Then if you want to add more accessories, remove one of the terminator plugs from the end of the five way connector, and add another spur cable in its place.
This is an incredibly simple install..