Excellent Todd, glad to have you (and by proxy them) here! I'll keep it simple and biased ;-)
Get them EGO Twists with 2.4-2.8ohm clearomizers (stardust/vision) and some 24mg nic
juice (and a backup of 16mg, even some long term smokers end up being suprisingly intolerant to high doses of nic). Load up the clearo's, set em on 4.8v, and kiss the analog's goodbye! If, on the off chance that doesn't do the trick, then you'll need to break out the big guns and get them something that will go to 6v and then have them use DCT
tanks. There's a lot more cost in this though and the
tanks take some maintenance vs. the clearo's so that's why I always say start with the twist. If you end up having to go the latter route then the Twists will still make great backup devices. Low end it's hard to beat the EGO's (as I'm discovering in another thread). High end (prior to going radical) it seems hard to beat the Provari but it's spendy and there are a lot of other good options in that arena.
Good luck man!