ended up going with a straight ahead file server, that won't need much processing overhead and will just dish files. This is kind of a "starter" system until I can get a bigger box going with a little more grunt and maybe a ZFS system with an SSD cache. I need to play around with that in the background a bit, but want a little bulletproof NAS for now.
I found out the HP n54L microserver runs the Sinology open source software build (xpenology) great out of the box, with a firmware upgrade and a better NIC card dropped in. You get performance at about ~150Mbps, which is about the same as the sinology 412+. should set me up well for a bit until things get revved up, at which point I'll transition over to the other server and use this one for backups.
all good, in theory anyway!