James, I feel your pain. Setting this up can be royal PITA. In my experience, the most user friendly server is JRiver. An additional advantage is JRiver also has a build in DLNA server, which allows you to use your PS audio bridge with minimal configuration headaches. What I would do if I were you is this:
Install JRiver 17 on your PC
Install myRiver on your iDevice
Install PS Audio's eLyric on your iDevice
Store your music collection on your NAS, preferably as FLACs.
Connect your PS audio bridge to the network over ethernet
Connect your PC to the PS audio DAC using USB - You probably need to download and install PS Audio USB drivers for windows. Check on the PS audio site.
Point JRiver to the music directory on the NAS as your main library, and load the library.
Setup your JRiver as a DLNA server (this is an easy configuration option)
Setup your JRiver for WASAPI output
Setup myRiver to control your JRiver 17 remotely on your iDevice
Select the PS audio DAC as rendered and JRiver as source in eLyric on your iDevice
You can now play music both over the USB input and the bridge.
I know it sounds a little overwhelming, but every step I descibe here is well documented and instructions can be googled. I have gone through many permutations of software hardware, and this is by far the most robust, foolproof setup I have come across.
myRiver is more stable than eLyric, so USB may be your preferred signal path. The bridge controlled with eLyric should sound a little better though. If you cannot get the bridge to work, just forget it and stick with USB.
Good luck!