Just this past week I was just looking (deeper) into building one of my own. Then I got distracted by some that were already available, but I can't find them right now (I delete browser history frequently). They are few and far between these days, but here's what I can recall at the moment:
Red Sky
mods apparently makes some now & again. And PBusardo just did a quickie review of the SVA
mod here,
A PBusardo Review - The SVA Mod - YouTube (should link to about 11 minutes in).
And, of course, there's the
http://www.e-cigarette-forum.com/forum/modding-forum/560010-printed-dna30-bottom-feeder.html thread right here if you want to make one from a 3D printer.
I'm sure there were others, but I can't access that part of my memory right now. I have true RAM.