With the right equipment coil building is quite easy, you will need.
1 Wire (kanthal, Nichrome, SS316, depending on your preference).
2 Coil winding tool (I use a Coil Master)
3 Accurate ohm meter
4 Cotton
5 Lots of patience
Making your own coils isn't for everybody, there is a learning curve, After the initial investment you will save money. It has turned into a hobby for me, but I'm semi retired so I have spare time. The most important thing is safety, don't make coils that have too low of a resistance. A lot of people think the lower the resistance the bigger the cloud, which is true to a point, but if the resistance is too low the only cloud you will get is the cloud your battery makes when it blows up. Regulated mods will shut down if the resistance is too low, so it would be best to use a regulated mod, the mods you mentioned I believe are regulated.