Would suggest a ego twist so you can play with the voltage. As an electrician of 22 years, there are acceptable deviations in ohms. A twist will allow you to fine tune your voltage settings to allow you the best flavor/vapor combo you enjoy. Just my two cents. As for delivery system, it is all up to personal tastes. I find a dual coil cartomizer or a viva nova tank work well for me. I am trying the Tabac BCC Cartomizer right now. I find that the bottom coil feeds better, but for some reason the flavor seems muted- even after 3 tanks full of juice.