Well, if you do indeed get a Provari, you won't need a low resistance cartomizer. In fact, Provape advises against using them. A standard (2.0-2.4 ohm) or better yet high resistance carto (2.5-3.0 ohm) will provide a wider range of voltages to use on a variable voltage PV like a Provari.
I use Ikenvape cartomizers in my cartotanks. Either the Platinum or 510 Fusion. They are a popular, limited-production, premium cartomizer and often out of stock. The pre-punched ones go fast, but since you won't need those you might find some un-punched.
If not, either Smoktech or Boges are the popular choice. People prefer one or the other brand for personal reasons. I recommend trying a 5-pack of both brands to see which YOU prefer.
The difference between the v2.0 and v2.5 is strictly cosmetic. Both have the same inner electronics. Consider a slightly cosmetic blemished Provari from the clearance section to save some money. Still considered new and with full warranty.
Clearance
I recommend only getting the Provari of your choice, an extension cap (if you want it) and the extended warranty (if you want it) and nothing else. You can get a charger and AW IMR
batteries from RTD Vapor for cheaper.
RTD Vapor AW Batteries