You did fine. I personally would have recommended the Kanger Aerotanks over the Protank 3's because of the new adjustable airflow bases they use. They're completely sealed from the battery with the holes being on the sides of the metal, rather than the 510 connection. This prevents leaking, flooding and gurgling to happen as often. However, fortunately for you, you can purchase 2 of these bases for your Protank 3's and they're fully compatible and work just as well for about $6 each if you can find them in stock. They're well worth the money.
The mini protank 2's are probably the greatest tanks Kanger has ever made in terms of ease of use. They never leak, gurgle or flood and apart from their smaller tank capacity, they're one of the best clearomizer tanks I've ever used. You'll love those things and they'll sit a lot more flush with your battery than the Protank 3's will.
In terms of you wanting to upgrade and what to? That all boils down to what you want out of things. If you want to go basic, but get more features out of what you use as well as battery life, then the MVP 2 is a great option. If you want a little bit of a learning curve, you can get into more advanced regulated mods like a Vamo V5, iTaste SVD or even a Provari if you want to skip the Chinese made models and spend the money for that sort of thing. Those take removable batteries and you won't be left with a dead device if your internal battery fails on you, that you may experience with devices that don't (eg. MVP 2, Twists, Vision Spinners, etc).
You also have the option of carto-tanks that are absolutely fantastic if it meets your needs. You have rebuildables such as RBA's, RDA's, etc that you could get into if those fit your needs. There is a massive variety of devices and toppers that you can get into to fit your interests and hobby of vaping. At the end of the day, all of them will produce vapor and deliver your nicotine fix that you so require to avoid analogs.
In terms of your current setup, it works absolutely fine and you'll get a great vape out of it. I really hope you stay away from analogs. Start watching some videos on how much tar you inhale every time you smoke one of those things, it really changed my views personally.
A link to the aerotank bases, so you know what to be looking for if you decide to get a couple:
http://www.sun-vapers.com/buy/kanger-aerotank-base/