If using a 330 ohm resistor, the max current is 15ma, the 220 ohm resistor bumps that up to 23ma. Whatever wire you have handy will be plenty big. I've been using pieces from the cat5 twisted pairs that I cut off making my aethers.
This resistor is a "pull up" resistor on the output data pin. The pic grounds the pin to make a logic zero, when not being grounded, the resistor pulls up the voltage to make a logic one. When the pic grounds the pin, the resistor is effectively connected between +5 and ground, which is when you will pull the max current through the v3 mod wire.
The 47 ohm resistor raises the max current to 106ma, which can cause other issues if the cat 5 is long or you are running a lot of nodes off that controller. I strongly advise all ssc v2 owners to either mod them to a v3 or at least replace the resistor with something a little bigger...