[Caver]

WWG,

You want to minimize the voltage drop so the wire size depends on the distance and current. Check the instructions for your charge controller. With 180 watts of panels at 12 volts I used stranded 10 gauge wire. I actually had the factory pre-wire it for me on my 2004 3023. There should be some photos posted. The 2619 doesn't have as much room on the rear shell to mount the solar panels so mounting on the front is your best option.

As far as the specific wire the finer stranded the better. In an RV wire gauge is a compromise between efficiency and weight. I have the smaller diameter plastic wire shield around mine. You can buy these in automotive stores.

Let know how it's going. Ray