The difference betwwn 2.0 and 2.5 is purely cosmetic. Both have the same inner electronics. The same is true between the regular Provari and the Mini. Same inner electronics. So, compare the two body styles and choose the one that most appeals to you. For myself, I prefer the newer Mini version despite it having a "busier" engraved look.
For chargers, I recommend getting what most people agree as being the best charger for years, that being the Pila. It uses a patented charging algorhythm that charges faster yet is safer and allegedly may even extend a battery's overall life expectancy. I've had one for almost a year now and couldn't be more pleased with it. Get a couple more additional spacers if you are going with the smaller batteries that the Mini uses. If you can't afford the Pila, I've heard the Xtar and Nitecore chargers are also good.
Of course, use only the button top, AW brand, IMR batteries that Provape recommends for the Provari. Never skimp quality for price with batteries and chargers.
I also recommend getting only the Provari, the battery extension cap (if you want that) and the additional warranty (if you want that) and nothing else from Provape. As much as I love the company, their accessories are overpriced and of questionable quality and consistancy. Not a fan of their cartomizers or tanks, you can do better elsewhere.
Purchase your charger and batteries from RTD Vapor.
RTD Vapor AW Batteries Grab the appropriate sized plastic battery cases for safe pocket or purse storage of spare batteries. They also have one of the largest selections of inexpensive as well as high end drip tips anywhere.