It is true with FA that many only need 1-2% and some need way less and only a few will need more.
Try
Eliquidmart for sampling FA as thye have 5 mL bottles for $1.69.
From FW, my must-haves are Yogurt and Banana Split. The yogurt is so authentic it's not even funny (to be used at 4-9% or thereabout) and their Banana SPlit I use as simply banana since it is the one banana concentrate that actually taste like mashed bananas and not green banana or banana candy.
I can probably come up with more to try later, just right now those were the two from FW and from FA it's any number of concentrates, but not their tobaccos -- mostly fruits.