Go slow. It's good to be ambitious--especially if you're vaping to try and quit smoking, the hobby of trying to find what you like/trying out new things/getting more advanced with batteries and building your own coils helps more than anything else, in my opinion.
However, it's very possible to get in over your head, especially in the world of ohms, appropriate battery amperage, and appropriate wattage.
I'd go with something like a Kanger Subtank or Subtank Mini as your next step (get the guys at your b&m to help you out getting a not-too-advanced mod/battery suited to sub-ohm vaping).
That way, you can use Kanger's standard .5ohm (I think..?) OCC coils, or, on the same atty, you can at some point try building your own coils on the deck Kanger provides. That's the great thing about the subtank--you can venture into the world of rebuildables at the same time as staying in your comfort zone and not finding yourself lost.
(Sidenote: For an RTA, since you're interested, you're going to get some pretty damn amazing clouds off of the Kanger Subtank.)
I moved on from my eGo/nautilus mini setup to a Kanger KBOX and Kanger Subtank, started rebuilding my own .7ohm coils with 28ga kanthal not long after on the subtank (note: get an ohm reader, and do your research so you know what you're doing

), and now I have a Nemesis mech and a few other mechs as well as an iStick 50w, which I interchange with my Plume Veil, Magma, and Omega RDAs, with which I am confident rebuilding and experimenting. Looking forward to trying new things. A Tugboat's one of the next items on my vape budget list. XD
One step at a time really is key, as is doing excessive research.
Sorry if any of this sounds like I'm underestimating what you're capable of doing; 1) it's not clear exactly where you are in your "vaping journey"/what you might feel comfortable with, and 2) most importantly, the very last thing you want is a dangerous battery situation on your hands.

Best of luck to you
Edit: sorry if I'm a little late to the party with this response, it seems like this thread has moved on through other topics.