If you are going to use the PS Audio PWD with integrated bridge (which is what I will be doing as well), you don't really need to worry about the quality of the storage since it doesn't have any affect on the quality of the audio. In that configuration it literally is just a file server - the bridge converts the file to digital stream for the DAC and keeps it in the optimal I2S format.
Forget about all the fancy NAS boxes with partial operating systems and integrated CD drives & ripping software - cool as they may be you can spend half the money and get twice the value with off the shelf stuff. Instead, get a simple 1TB NAS and stick it in the closet with your router. While you are at it, get a 1TB USB drive to back up all your files too - $350 will probably get you both.
Software wise, nothing beats Exact Audio Copy (EAC). If you don't like the complexity of it, then Poikosoft Easy CDDA has a much friendlier interface and has integrated many of the same secure ripping features - it will cost you about $25 I think. If you have a ton of CDs and don't mind paying for it, there are services that will rip everything for you and send you DVDs of your ripped files.
Have fun!