And there is your answer. And a fat battery model should also let you use low resistance cartos etc
As for things with your current batteries - with no adapter you can use DSE901 standard atty and carts (or drip tip which is only recommended if you have manual batteries). With an adapter you can use a 510 atty and there are probably some other adapters. If you are looking for more power - 510 batteries are a bit lower voltage so using a standard 510 atty on a KR8 battery may run it hotter than on a 510 battery? With the adapter you could also try 510 blank cartos. Just don't put LR (low resistance) attys or cartos on a slim ecig battery - their internal electronics may not be hefty enough for the power draw and you could kill the battery.
And I don't know, but maybe with an adapter you might be able to use ProVari or other variable voltage PV with KR8 cartos?