I like your system - I have Sf Nova's as well and I previously owned McIntosh pre and amplification.
I am biased towards DAC/streamer due to space and simplicity. I started with Node 2i, then moved up to Moon 280D and now I have Moon 390 which is also a preamp. The Moon 390 replaced my Moon 280D and McIntosh C2600...it was an upgrade for both. And I sold the McIntosh for more than I paid for it.
If you like the streamer/DAC that happens to be a pre-amp. I wouldn't shy away from it. Your integrated amp can be used just as an amp and if you decided to go to components a streamer/DAC "Network player" provides you flexibility in transitioning to separates (such as MC 312).
Good luck in your journey!