I have bought from both Nicotine River and Liquid Barn. I would Highly suggest going with Liquid Barn.
Or Heartland Vapes. Another Good source of Nicotine Base, Flavorings, Bottles, etc.
But whatever you decide on, I would do it Quickly. Like Tonight. Because we are in sorta a Limbo right Now of Can and maybe Can Not be sold.
And No On knows exactly How Long things might Last.
BTW - Liquid Barn has a Calculator that help estimate How Much Nicotine Base one might. Here is a Link ...
Vape Apocalypse Calculator