Get the NDX2 first. The ND5XS2 is great value, but it’s performance is not in the same league as the 282/250. For a balanced system you should be looking at NDX2/XPSDR. Now could be a good time to get a good deal as people trade in their NDX2s for the new 333.
(Alternatively consider a DAC upgrade and keep the ND5 which makes a great transport, as this can be a very cost effective alternative to PS upgrades on the NDX2.)
The presented options make me wonder if you’ve asked yourself the right questions. If you like the OC sound I’d just continue with the separates path you’re on and take advantage of current discounting. If your goal is to move to the NC then I’d look at going 222/250NC.
First I was interested in getting “just” the NSC222 instead of my preamp section with the supernait and my nd5xs2. But now it would be possible to get the nac282/nap250dr-combi for a good price - that’s the reason why I’m thinking about these 2 options…
I think as above, the best answer is to listen to both yourself & decide. They both have a different sonic signature & as with most things in audio, opinions will vary. Most peoples recommendation will just be based on what they currently prefer. What you listen for, what your speakers are, what your room sounds like, etc, etc, etc, all have an impact on what the correct answer for you is.