I would just say take a look at
mooch's blog and take a look at his recommended batteries. Depending on what Wattage you run at will help determine the batteries for you. I use LG HB4s (mech/power) and Samsung 30Qs (life). Although that
smok takes 4 batteries so you would still be able to run up to ~240W on 4 20A batteries (at a low 3.0 Volts).
My 3 battery triades will run the Samsungs, and my single battery mods will run the LGs. But I know where I build (single/dual coil), and don't really deviate Wattage wise much. I know, boring land.