While the GSE adapter does look like a rather attractive option
(namely, because of how you placed the fans), i could still mod my
vulcan with a DC-DC adapter made for a mini-itx case for much cheaper.
The only drawback is that my //e will have a AC/DC adapter brick on a
leash. :-) But it will also run a lot cooler for sure.
Seems a lot of flex atx power supplies would work, if not look a little
silly because they're much smaller. Some SFX supplies might work
except their fans point straight up at the top of the case (I'd
probably have to rout the airflow, if that's even feasible)