For a reminder of the situation, see my previous post: NineBall Versus the Audio Formats.
Well, as it turned out, I was doomed from the start thanks to the "genius" of Apple (see what I did there?). Apparently, DAAP servers are totally cool for transcoding/sharing media with iTunes but you still cannot sync shared music to your iPod as that breaks some magical DRM law. If you want to be able to sync media to an iPod from a central source with iTunes, you have to set each PC's iTunes folder to the same network share. This will mean setting up the same mapped drive on each machine so that iTunes can use a central database and not get confused and will also mean not being able to transcode media, so no FLAC.
All-in-all, Apple really boned me on this one; proving once again why I hate their closed system and always recommend their competitor's product (most recently convincing family looking for an iPhone to get an HTC Android device). The result here being that I will rip all of my audio CDs to AAC for native compatibility with all my devices but the DSM-320 which can be serviced by a DLNA/uPnP server.
As a side note, Firefly worked awesome and did exactly what I wanted it to; transcoding FLAC and allowing it to be playable through an automatically detected shared folder in iTunes. I won't be installing it on my server as I will be using the direct access method through iTunes as noted above but if my main concern was simply allowing shared music on multiple machines through iTunes, I wouldn't hesitate to recommend it. Subsonic was not what I thought it was although it is pretty cool for what it does; which is to allow you to listen to your music from the server through the internet as a streaming music site. I could not get FLAC to work with it, but since I will now be ripping to AAC this will not be a problem if I decide to install it on my actual server for remote access to my library.