lots of places, i prefer vaperstek.org 'premium' unflavored nic and vg but, many like freedomsmoke, wizardlabs and others.
the carolina
tobacco concentrate however may not be the same everywhere. you would think they were of same strength but, with my favorite SC french pipe
tobacco, it turned out that was not the case. So only place i can recommend you buy the SC carolina tobacco favoring is from
vaping zone since that is the one i used (and also now only use for my SC french pipe too).
SC-Carolina Tobacco Super Concentrated Flavor .
they sell nic, vg, pg, etc too but, prices are higher than they should be IMO so up to you if you want to buy those from them too.