Parasound and KEF is the pairing Richard Schram of Parasound recommended to me when I asked him that question.
If you go with an active speaker the "magic" is done by the speaker designer where he matches the amps with the actual drivers.
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.