Any questions you have, just ask.
For $40 you can get the T-Rex at Liberty Flights. Comes with dual coil cartomizers but you'll need to purchase a wall charger.
That has a 900 mah battery . You get about 1 hour per 100 mah.
Electronic Cigarette - Starter Kits - MEGA T-Rex
Or there is the standard Riva for $29.99. Comes with two batteries, 2 atomizers, cartridges, charger. Purchase cartomizers separately.
With the ego battery you have several options-
Cartomizer & battery - the cartomizer is a cartridge and atomizer combined. You attach this to your battery. You get a good vape with this and it's very easy. The downside is, that when your new, once you fill the cartomizer with juice your committed to vaping over 1 ml of that flavor.
Cartridge, atomizer and battery. The plasic cartridge holds juice and you place it on the atomizer. This gets placed on your battery. Cartridge doesn't hold as much juice as a cartomizer but can be cleaned and reused. Messier and sometimes leaks.
Tanks (ego-T) Small tanks filled with juice, placed on the ego-T atomzier and placed on your battery. Easy to use and you can tell when you need to refill. Can be reused. Downside, vape is muted somewhat and they sometimes leak or get dry hits. Issues with the Wick.
Dripping- Drip juice directly onto the atomizer.
There are also CE2's, dual coil cartomizers, etc. etc. Very versatile pv.