LiteCigUSA for standard resistance 306 atomizers and cartridges. Do not buy LR (low resistance) - those are only for 450mah+
batteries and can damage a slim battery.
No idea where to get 306 cartos. Can't you just use 510 cartos? try some Boge 510 standard resistance cartos from the same place. But be careful filling your own cartos with auto
batteries. You need to full a carto fully (like 18+ drops) and clean it up and let it settle (I lay on different side 15-20 min) to get all stuffing damp. But sometimes one will still leak and then bye bye auto battery is a possibility. Try 16 drops with auto batteries- just make sure to let the carto settle well and be insane about cleanup - you want that central air channel clear (I blow into the threaded end with open end down into a tissue) and I sop up any loose
juice above the stuffing.
I recommend you go read the Blu forum.You can't post there yet
Blu Electronic Cigarettes
And for future reference - never charge 510 batteries on a Blu charger or PCC - Blu is reverse polarity and its charger and PCC can melt 510 batteries. And vice versa.