Are you talking about the big or little Chuck? Cuz I don't really want to lug that in puplic lol!
The Chuck doesn't do 5V without further modification.
The Xhaler, however, might well be a great starting point for you. If it turns out that you don't like the size for public display, you can still use it at home, but I went with the Xhaler so that I could try the various voltage settings and see which one I liked best. I haven't tried 7.4V yet, but even at 6V there is a burnt flavor that I dislike and I doubt it gets better at 7.4V but I'll try it with HV attomizers because they should bring it back down into the 5V "sweet spot" vicinity.
A unique feature of the Xhaler is that you can vape at 5V, but then as the voltage drops off as your batteries drain, you can loosen the bottom cap to bump the voltage back up. As far as size goes, the mod itself is 4" (100mm) tall with a 3/4" (20mm) diameter. With an adapter and 510 atty/cart it's 6 1/4" (160mm)