Protanks (I and II) work directly since they have 510 threads, and honestly, I suspect you won't like the look of an Evod (which has eGo threads-thus will require an adapter) on the ProVari. I use Evod heads in my Protanks all the time they work great.
EDIT: The Protanks are pyrex so they will not be cracked by corrosive e-liquids. Get an extra base or two, since they tend to break if you drop your PV. They are only a few bucks and well worth the investment.
EDIT II:
Here's a Protank on my ProVari. It looks like it belongs there, does it not?