Hi dskarpus,
I'll try to help some... I started with the RN4072 from another company (and still use a penstyle everyday). It seems that the RN4072 isn't being made anymore... so you'll just have to start buying 801s. Frustrating, but that's the way it goes with models being made by different companies.
The 4072 is usually compatible with the penstyle DSE801 however, I have some that need a bit of tweeking with to work with each other. The center post sometimes is a bit shorter when mixing parts, and to solve that, I either will lift gently on the center post of the battery with a paper clip inserted in the hole, or will solve the connection with the "staple modification"
http://www.e-cigarette-forum.com/fo...-center-conductor-gap-penstyle-atomizers.html
I'd like to suggest (and I learned the hard way) is that you buy several 801 batteries and matching atomizers if you can, just to ensure you don't have compatibility issues and so you can start building up parts made to work with each other. Sticking with one Supplier for a model is a good idea (and you've picked a good one here!) :waves at Ed and David: Customer service here can't be beat.
On the passthrough plug in, I use one made for an Ipod and it works great! I think as long as you get a similar type (made for Ipod) you should be fine (available at BestBuy, but if you can wait, you can get one from Deal Extreme on line for only a few dollars each).
You also can buy a Kensington USB rechargeable battery pack from BestBuy (I can't tell if you are in the USA, so you might want to update your Member information so others can more easily help you). I understand the Kensington is on sale right now for $39.95, and they do go on sale about every 2 months or so. I bought 2 of them to use with my passthrough, and it solves the plug in and battery issue for an entire day for me.
Regarding your other models (I have never used those), you might want to look in the model specific threads on the forum:
Model Specific Discussion or maybe someone else can post info. here for you.
Vicky