One of the best machines in the market,and def one of my favorites.. In my part of the world I haven't found anything to really compete with it. Not the hardest machine but it takes time to understand it fully. Good luck, I recommend starting in de mode, 3h tones and sensitivity cranked. Actually that's pretty much what I use always,and been running the f75 a long time..As for coils, maybe a 5 inch or similar but don't buy anything else,waste of loot. That stock coil is the best for that machine.