I've been meaning to look for info on this myself. All the parts are out there and readily available. Just a matter of having the time/money to experiment, and get it right.
510 Atty ...'y here:
510 Atomizer Connector, Assembled
While I've seen some jokers using cheap plastic project boxes, a la Radio Shack, most quality builders are using Hammond's metal 1590 Series enclosures. The same ones typically used for housing guitar effects pedals.
The 1590's are Die-Cast Aluminum, and in perfect sizes for a mod. Problem is that a DNA mod requires some unique machining for both the screen and USB port.
Back in the day they only sold raw, solid boxes, unpainted and un-drilled. Now there's companies out there who not only offer painting service, but also offer custom drilling services on a minimum order (usually 10+ pieces). It's not cheap ($3 per hole for the first 6 holes, $.25/ea after that), but if you were doing a resale at the going DNA mod prices, you can make out nicely.
Enclosure Drilling
Trouble is, if you only want one or two drilled enclosures you're screwed. I'm not aware of anyone who will do the custom drill pattern necessary for the DNA screen on a smaller order than cited above. If anyone does, please reply. I suppose just buying the bits, and supplies to effectively drill and bore aluminum would be more cost-efficient for a small batch of 2/3 mods. It's just a headache I'd rather avoid altogether.