I also use a 2-channel (or 2.1) system for video. I think your approach, selling the center and surround speakers and processor, would be a good way to go. I would keep the amp for now as you are satisfied with it. Can always change that out if desired.
The Node2i mentioned by williewonka certainly has the features you are looking for and with your budget you could use it with better DAC. I believe there are other preamp/DAC/streamers that could be considered. That option I will have to leave to others, as I will be in the market, however haven't as of yet explored the market, outside of this forum.
The Node2i mentioned by williewonka certainly has the features you are looking for and with your budget you could use it with better DAC. I believe there are other preamp/DAC/streamers that could be considered. That option I will have to leave to others, as I will be in the market, however haven't as of yet explored the market, outside of this forum.