You can't charge a battery through Bluetooth, so the Netbook runs off its own battery for up to 4 hours (typical daysail). When I go out for more than 4 hours I plug in a car adapter to a 12v outlet in my cockpit. That's the only wire that connects to the Netbook, and you can see it in the pics above.
More details on my setup can be found on this thread
from two years ago. You can see there that I have a central interface box that feeds data and 5vDC to the various devices. The box is mounted to the ceiling of the aft berth, behind the VHF radio and directly below the solenoid switch for my LP system:
FYI, the black wire in the upper left corner of the above pic is gone now - ditto for the white wire hanging out of the 12V panel. Those were temporary power cables used for testing. They have since been hard-wired with hidden cables. And the angle of that pic is meant to show the interface box - from a normal standing position, it is completely hidden behind the VHF and you do not see it.
The GPS puck and the two Bluetooth transmitters all get their 5v supply from this box. The Bluetooth transmitters are mounted directly on the box, and wires from all the external devices (VHF, puck, autopilot, 5v supply line) all plug into the box via RJ45 connectors, like the ones commonly used for Ethernet. This way I can quickly disconnect everything if something needs to be removed for service.
The Bluetooth transmitters are industrial grade ones from USConverters, not the Iogear ones that you linked.
The GPS puck is a different one than you linked, although that one would work nicely for many applications. The one I used is this one: http://www.amazon.com/Garmin-18x-LVC-Navigator-Unit/dp/B0016O3T7A