Gosh xcentric, your question certainly covers plenty of scope for changes!
If music streaming is your only source, then this thread may prove helpful:
A comparison of many streamers
You already have a lovely amp & speakers. Ruark always made deceptively good, properly musical speakers.
In contrast, very few streamers actually sound musically credible and “right” to these cloth ears. And you have gone and hit the bullseye with the DCS Rossini + clock. Once you have heard one of these, almost any other streamer sounds artificial.
So by all means upgrade your pre-amp, power amp, go active or buy Sopras. They will all give you better hifi but in the process will shine a brighter spotlight on the limitations of your streaming source.
So I would leave your amp & speakers well alone. In your position, I too would buy the Rossini + clock, then sit back and enjoy the marvel of truly great streamed music.
Best regards, BF