cd5xs/ndx/+p/s OR cd5xs/ndx/ndac

I can't understand why have a CD player with a network player no matter what model combo's, the idea is to rip CD's to a NAS or other storage media & play those files from the network player.  Additionally the NDX is sonically far better than CD5

For the price of those options you could probably get an ex dem NDS and XPS2, which would be even better. As Mike says, a CD player is superfluous when you have a network player. 

The nDAC is officially an upgrade to the NDX, so I would definitely build whatever solution you decide on around the Naim DAC. The nDAC is good on its own but yes, it does get better with a power supply. Second hand prices for non DR PSUs are very attractive. The DR PSUs are not necessarily better than the non DR ones, at least not on the Naim DAC. Which kind you prefer depends on what element of the presentation you place emphasis on. A simplified classification would be a more analogue sound with non DR vs. higher resolution / lower noise floor with the current range of PSUs. CD5XS into nDAC/XPS2 for example would be a stunning front end. A 555PS will take it further still but comes at a higher cost. 

Personally I would not invest in a new NDS unless I had the cash lying around spare. Even then I would hesitate. The nDAC gives the NDS a pretty good run for the money. Even more so, if you bought a pre loved one. At second hand prices the nDAC is an absolute STEAL! 

Although the nDAC does show up the quality of the bit stream it gets fed, I think overall this is secondary in terms of musical engagement. Hence I wouldn't go above an ND5XS as a bit stream provider into the nDAC. Certainly not, if my amplification was below 282/SC level. Rather then choosing a Naim streamer you might as well consider a modified Sonos Connect or Mac Mini instead. Sound wise you will be pushed hard to hear a difference between them. Cost wise these two options offer far better value for money over any Naim streamer. Each option offers its own advantages, so ultimately it will come down to one's own personal preferences, which of the three the individual decides on. 

My two pence. 

Good luck!

nDAC indeed! Only a very few have have indicated preferring NDX/555PS to NDX/nDAC/555PS for presentation over resolution.

Chag -