My assumption is that the DAC is going to play a much larger part in sound quality than the Streamer.
I disagree with this IME. Initially I thought the same thing, but everything in the streaming chain from switches to cables to streamers, for whatever reason, seems to make a big difference. Toward that end, I’d buy a separate streamer and DAC as both technologies are progressing quickly so the flexibility to upgrade one when a meaningful improvement occurs in the other you can just upgrade that and keep the other. And I’d recommend spending around 50/50 on the DAC and streamer to keep it balanced. You could do something like a Lumin streamer and a Gustard R26 DAC and have a really great combo that doesn’t break the bank and will likely be a significant upgrade over the Cambridge. Just one option to ponder, and best of luck.