Having never owned a Provari, I *think* it will read down to 1 ohm, but someone please correct me if I'm wrong. I would strongly suggest you get an ohm meter, that will not only let you test the resistance of your coils, but check for shorts, and is also useful for trouble shooting all sorts of electrical problems, and test your batteries.
Here's one at RTDVapor.
I would base what you get (mini or grand) based on how much ejuice you vape in a given day. If you're well under 3 ml, OR you don't mind carrying a few extra bottles with you, go with the mini. If you vape at or above 3ml, and or don't want to have to carry any "spares", I'd suggest the grand. It will hold a full 6ml, and I find the battery lasts me easily 24 hours (with sleeping in there somewhere).
Batteries should be chosen with safety in mind, I'm not familiar with the Samsungs, but AW IMRs are the recommended battery. Quite a while after that recommendation, several newer batteries hit the market, that are as good or better. I'm using Sony VTC5's. They have a 30a discharge capability, and are rated at 2600 mAH. Again,
RTDVapor. (I just checked and they are out of stock, but those can be found many other places as well).
I've been using a Pila charger for years, I find them quite well made and they always seem to charge the batteries perfectly.
Don't know if I linked this already, but here is a
chart of various coil resistances based on gauge of wire, diameter around which it's wrapped and number of wraps. You can figure the watts using any of the online calculators, but I'd suggest just start with the resistance you're used to, then adjust from there, by adding or subtracting 1 or 2 wraps.