Some of these mods don't include the battery, in which i have no idea where to get them
Battery Junction or Lighthound is good for batteries... I'd really recommend a Prodigy because of you dont like high voltage vaping, you can go back down to 3.7v. Puresmoker sells their prodigy in a kit - you pick either 3.7 volt or 6v - and it'll include the mod, 2 sets of batteries, a charger, 1 atomizer.
Also, a lot of e-cig supplier sites sell batteries and chargers (madvapes, ikenvape, cloudsofvapor, etc). Just make damn sure you get the right size batteries/voltage! When you decide on a mod and it doesnt happen to include batteries, just google something like "Best battery for xxxxx e cig" and you should find some info... hth, good luck!