Cartomisers are the refills for the cigalike type of ecigs, about the same size as the filter part of a normal cigarette and usually a different screw fitting to the standard 510 Ego thread. Though refillable cartomisers are available, most tend to be disposable.
Some clearomisers (aka clearos, tanks) e.g. CE4 are disposable so when the coil/atomiser dies you replace the whole thing. Others (e.g. CE5, GS-H2s) you can replace the atomiser in the main tank part.
I'm guessing the "kits with the tank" thing is the Kanger mini Protank? The Protank tanks are made of Pyrex glass so less likely to crack if you drop them, plus certain flavourings in the juice can damage the usual plastic tanks (e.g. some spice flavours). The Kanger Protank tanks can be taken completely apart, and every bit is replaceable.
Be careful of Fasttech - in a good way! I ended up buying exactly double what I'd intended, they are just so cheap and tempting
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