Provari is clearly a good pv, many happy users.
Notcigs buzz pro, or the lower cost infinity pro are both very solid pv, well known supplier, excellent performance, US built. They provide good run time between recharges, can handle higher power than provari or lava tube, excellent durability, very simple to use (just a voltage adjustment wheel and the button to fire them). Whether an lcd and button user interface is a plus or a minus is a user choice.
Lava tube is new, about the same price as the infinity pro by the time you add batteries and charger, has the lcd and button user interface, uses the boost technology and a single battery compared to the notcigs buck approach. It will likely have some new technology teething pains, but looks like a decent, nicely priced, vv.
Madvapes sells a low cost vv, very affordable, too.