I really can't tell the size from that picture.. de-solder wire and cut it count strands.. and micrometer size... there's international charts online that will give you what size ... you can always use a thicker gauge wire then use the amount of stands that will fit in pre drilled hole. but b4...
the ones with the plugs are coaxial wires like you home cable but that is much larger.what you want is a gauge sized wire .strand count will matter . not sure this is the right wire you need but 20 ga is .032"