Mechanical is the best choice for accuracy. Yes they do come with a nylon line and WARNING DO NOT KINK IT OR IT CAN LEAK. They do sell a copper line to replace the nylon more durable less prone to leak. Trust me on that! I kinked a nylon line in my classic and it leak within a few days and it is a mess to clean. Be carefull do it right take your time and all will be good.
