OK. Now having said that...back to the OPs question.
One mod does not fit all. Let's take a look a couple of things. I am of the opinion that when we make recommendations they should not be based on what we personally like but what will fit the owner best. At the end of it all, we want to help people enjoy vaping and quit smoking. Whatever gets the person there in the easiest way is the right solution.
1) Vaping has a learning curve.
2) Consider the user, their life-style and the environment in which the device will be used.
3) Consider the user's nicotine dependency needs
What do we know about your postman?
1) Assuming he is in and out of a truck all day and driving.
Conclusion: Mod and Tank must be rugged, high potential for it to be dropped and broken,
2) Heavy Smoker
Conclusion: Needs backup gear. Needs gear that is reliable. Higher juice strength to start. Initial investment in gear will be re-couped quickly by not buying cartons of cancer,
3) New Vaper.
Conclusion: Start with simple juice delivery methods so as not to confuse the new user. Obtain a mod which scales to more advanced methods and is safe.
4) Probably has no USB charging in the truck
Conclusion: IMR LI-On battery powered is best.
So based on the above, here is what I would recommend.
1)
ProVari Variable Voltage Electronic Cigarette Starter Kit V2.5
2) An ego battery as backup, just in case
3) A couple more Pro Tanks as backup or if the user can learn to prime a carto then these
22mm Cartomizer Tank
4) High nic juice (s) 18mg to 24 mg
I think the above is a reasonably priced sure fire solution to this particular vaper's needs based on what you have told us, OP. If there is a brick and mortar near by, maybe you could take him there and familiarize him with some options and juices.
LOL, I do system architecture for a living...so you just got a requirements based solution.