I tend to run mine on VV devices at about 4v. Of course, YMMV. Start low, 'cause you don't want to burn it. Once you do, you'll never get that flavor out.
I'm not a huge carto connoisseur, but after trying a half dozen different brands and types, I settled on the
Ikenvape LR Platinum S. They're often out of stock, so sign up for the email notification and be ready to order quickly; they're usually back out of stock after a day, sometimes less.
Now the bad news... I don't know if you're going to see a big improvement over your pro tanks and whatnot. IMO, the carto has a slightly cleaner taste, but the difference is marginal. Vapor production and hit strength are on par with a good Evod. I don't really use mine for performance reasons; I have a bunch of long-term, less often used flavors stored in those tanks. I can pull them off the shelf, vape it for 30 minutes, and put it back for a couple of weeks with no change in performance.
Personally, I don't think you're going to experience a big change in performance until you start getting into drippers and RBAs. I don't want to discourage you from trying the tanks, just don't go nuts with it right away.