I would suggest new
batteries, I don't trust any battery/charge with fire in the name. I solely use the sony vtc3 or vtc4, aw imr 1600 mah's or efest 1600mah for the high amp load capabilities.
for chargers the xstar, luc, and nitecore are really good
gauge of wire will depend on your resistance, I would start at 32 gauge since it sound's like this is your first step into rebuilding. It will take less space to make a coil above 1ohm which is a good starting point. The Igo-w3 doesn't offer a whole lot of space for building with gauges like 28 where you would need more wire to get the same resistance. Once you get more comfortable then you can play other gauges and lower ohm's.
for wick you can use cotton, silica, ekowool, peaches and cream yarn. I have tried them all and personally like the cotton balls.
also if you don't have handy you will want a mutli-meter or ohm meter for checking your resistance. and make sure you your
coils only touch the post from the legs, the rest shouldn't touch anything metal.