I have purchased cells from all the above places mentioned. I also buy most cells from a seller on Ebay, genuinecells. Some others on here also buy from them.

Link to a good charger.

https://www.ebay.com/itm/XTAR-VC2-PREMIUM-QUALITY-USB-LCD-CHARGER-FOR-3-7V-10440-26650-LI-ION-BATTERIES/112055740935?hash=item1a170aea07:g:hFwAAOSwuMFUk2Pq

Link to batteries good for just about anything. Order as many as you need.

https://www.ebay.com/itm/Lot-Quantity-Samsung-INR18650-30Q-3000mAh-High-Drain-Rechargeable-Battery/123148981707?hash=item1cac4055cb:m:m1Fnh7nXFuSRpcxhFScQjVw

Same seller on Ebay and free shipping.