I'm looking for something with great durability, and a battery that can last a long darn time! There are times when I'm working for 2-3 days at a time and don't get to charge my vaporizer...
REO: If you want to try a bottom feeder, a metal REO is indestructible, charge a bunch of batts up ahead of time, swap out as needed. Made from a big hunk of aluminum block, then powder coated or annodized. Mechanical mod, no VV, but it it gets wet everything still works if you drop in a puddle. You can give 'em a bath in the sink once a week (take out batts and coils, etc. ) Reo Grande takes a 18650, should last you all day on one batt. Stick an atomizer or mini shorty carto in there, put juice in the bottle and you're all set.
Provape-1: These are such nicely "weighted" and the way they fit in your hand is just divine. 3.7 device, no VV......but there IS some circuitry involved, so not rain-friendly. Very safe, very nice length and size, but 14500 batts you will need to change out 2-3 times a day depending on how much you vape. However, those batts are same size as AA's......so niice and small, lightweight and pocketable, and get yourself a few battery cases to put them in and you're good to go. Couple nice little tanks fit on there nice, or a clearomizer.
(same situation with the smaller REO "mini" ..... 14500 batts)
Provari IF you get one they are thicker and heavy...so get a flexi wrap from serenity gear ... it has a hook to attach to your belt, and these are thick durable leather wraps/loops. Again, circuitry, so not entirely rain-friendly.
you said oil patch, so I am thinking of conditions at pipelines and/or offshore rigs......I
know the environments......(brothers all worked in conditions).
If you're moving around a lot, IMHO a Provari could prove cumbersome. I know a lot of loggers and they said they couldn't deal with it.....but everyone is different.......I don't suggest a provari for you at all.