Really there is no comparison for liquid in comparison to a pack of cigarettes. This is a fictional concept at best. For starters the absorbancy rate for the nicotine in eliquid is low and the only comparison you could go by is puffs per cigarette. This will be different for everyone and not worth lighting a cigarette to find out.
Silver bullet from http://www.altsmoke.com , Atomizer 510 from http://www.h2osmoking.com , Driptips from http://www.nhaler.com , and some CR123 batteries from http://www.batteryjunction.com . This will give you a great vaping experience.