I use 0,20 / 32awg kanthal, and 500 mesh. You could use either 300, 400 or 500 mesh. I dont really think it matters, because you can choose to roll it tight or loose. ... just preference.
The kanthal could be thicker if you use a mech mod, but 0,20 should do the trick.
If you roll a small piece of baking paper on the mesh wick where it goes through the top part of the tank, it will be easier to set up, as it will behave like an rsst, and the bottom coil will light up easier. Whis is because you will avoid the current going from the top part of the tank and into the mesh
I just got mine to work better now, but stil need a washer. All coils light up evenly though, but with a very small hotspot on the piece of wire going to the centerpost