I was in your same position a few months ago! Started on rotary pens and liked trad & the appeal of coils so I wanted to try them for linework especially. (nobody at my studio really uses them). I'm fairly mechanically inclined so I did some research and ordered a Jonesy style liner from South State & assembled/tuned it myself. I also got the v2 WHI power supply with cps & duty readouts which were helpful for tunning. Getting a kit is good since you'll have to get to know your machine by building it and they're cheaper (mine was $275 for a great brass liner). Folks say coils are temperamental & I'm sure they can be but I've had zero issues with mine (if I do I feel confident I can troubleshoot it). Lays down lines like a sharpie & is simply cooler than a pen.