Sorry carts and cartos are two different things. Cartridges "carts" come with the kit and there really is no real reason to buy anything else, it is personal preference. Cartomizers are a combination of atty and cartridge in one unit. They can be prefilled or you can fill them yourself with juice. They screw on the end of your battery like an atomizer and will last about 4-5 hours (in my experience and depending on the cartomizer you choose, I'm just referring to basic cartos) and are the easiest for using on the go.
Oh, and in my experience, the waiting game with Liberty Flights isn't very long. I normally get my orders in 3-4 days after placing the order. Of course, it is Christmas time, but I still haven't received some shipments from Wally world that I ordered the same day as an order from LF. From west coast to east coast in three days, sweet.
PS If you didn't order a drip tip and want to sample flavors without wasting alot of juice in cartridges, just take out the filler from a cartridge drip a couple drops right on the atomizer and put the empty cartridge on the end of the atomizer and vape it. It is like dripping with out a drip tip and actually gives an easier draw.
