Its all up to preference, every one says something different works for them. I preferred Nichrome as it was easier to work with. But the Kanthal I used let me get hot vapes
The guage of wire you use will also affect the resitance of the coil you end up with. If you have equal lengths of 0.16 and 0.2 guage the 0.2 will give you a lower ohm coil.
I'd go for 0.2. Bought some 0.15 for my ce4's and vivi nova and you don't get many coils to get the right resistance. If your making a double coil it's fine.