I would recommend Stainless steel 316 wire i have added a link for the RBA but if you spend another $5 on the site it will give you a free shipping option. Building coils is a pain at first but then becomes easy and is so cost effective its worth doing. You can also buy a few tools cheap, ie wire clippers, coil winder all you need then is Cotton and your ready to go. Smok coils are expensive for the 3 packs arn't they but you may want to try these sights ok they are in China but the savings are worth the wait i use the sites for most of my vapegear
fasttech
Gearbest
focalecigs
3fvape
Cigabuy
2fdeal