For now, it ain't that differacult.
buy any of these for your itty-bitty 18650 mods:
LG HG2
Samsung 30Q
LG HE4
Samsung 25R
LG HE2
Sony VTC5
Sony VTC4
Maybe in that order, but there ain't all that mucho difference betweence. Pick a color.
(Did I miss any?)
And only buy from:
illumn.com
rtdvapor.com
orbtronic.com
liionwholesale.com
imrbatteries.com
(There are other fine vendors, but these are sure bets.)
And you'll be safe and sound.
(Always stay away from gerry's fire-starter bargain-bin batts. )
If ya need 18490/18500 or 18350, it's AW reds all the way.
And don'tcha worry about $0.04.
DPL can cover ya.