What I do is use house wiring "Romex" cable with the sheath removed. You will have a black wire, a white wire and a bare copper wire. I use the black wire (+) and the white wire (-). The Romex wire will be solid, not stranded; and it will be my main buss wire. I use my pocket knife or a utility knife to cut off the insulation where ever I want to hook in a drop lead. The drop lead is soldered to the track on the outside of the rail, tucked into the center of the road bed and a hole drilled to allow it to go through the bench work. I also use color coded drop wires to make the wiring easier. Now strip back 1/2 inch or so of the drop wire, and coil it tightly around the stripped section of buss wire. Use a soldering gun and rosin core solder to solder the drop to the buss and you are good to go. For most reliable operation, every piece of rail gets it's own drop soldered at both ends of the drop. Since there are no reverse loops in your plan and you are running dcc, one set of buss wires will do the entire layout. If you were running dc instead, the wiring would be more complicated.