"Are their known magical PAIRINGS of integrateds and small bookshelves?"
I think there are known magical pairings of ears + speakers + amps + music + room + time of day.
Sorry if it was a bit "vague" :)
Just reporting out that I ended up going with Elac Navis ARB51 powered bookshelves and a Topping Pre90 preamp. (A single DAC can feed both systems so I think of the "secondary system" as being everything after the DAC). For around $2500, I am happy with this combination, which is very small footprint, simple, and is fine for most casual listening. I don't really have a refined sound quality analysis to provide here, other than that the combination generally sounds pretty good, considering the small size and budget (not tremendous bass or sound stage). I am running the speakers with RCA cables in (not wireless) consistent with at least one review article that said SQ suffers over wireless.