@allareas, i have not tried vaping tobacco with hash but i warn you of two things:
1. i tried vaping street hash, no tobacco and got a huge headache so if you plan on vaping hash, make sure is top quality. The type of hash that either crumbles in your hand without heating and wasn't pressed or that thick gluey dark morocan hash.
2. Tobaco has a vaping temperature of roughly 190C, im not sure if it is okay to go until 220C-230ºC, plus it is really easy to over indulge with tobacco since it is WAY more powerfull to vape tobacco than to smoke it.
And a nicotine high is not pleasant at all if you over use it.
So, i'd strongly advise you to research for people who have done the same and their results, but i'm guessing you should vape them separately.
Convection works better with tobacco and conduction works better with hash. Still, i'd prefer a convection unit if i planned to do both like you want.
I'd use a unit that you could swap the setup to just herbs without using exactly the same material or material that easily cleans thoroughly. I wouldn't use any vapes that have wood or plastics in the vapor airway.
Since you want convection portable, i'd say the Lotus is your best bet. Perhaps the hammer is an even better bet as well since you can use different stems.
I'd steer away from firefly, and vapman in this instance, especially since you plan on trying tobacco with it.
But, to be honest, i wouldn't mix them in the same session. Vaping hash is VERY sedative, much more than smoking it, if you had tobacco you'll maximize the effects to a point it might be too much.
And vaped tobaco leaves a strong taste in your vaporizer from what i've read.