Imo, all the speakers suggested here are worth auditioning.
But my thoughts on some of them:
Monitor Audio (neutral sounding to me) works great with Marantz (slightly warm) and NAD (warmer) electronics,
Kef Q500 (bright, overpowered bass) were not so great on Marantz but listenable on Nad (when you turn down the bass), but they need a pretty stable amp that can drive speakers with low impedances since they dip to 3ohms. The Q300 is easier to drive (dips to 4ohm) and has a more neutral sounding bass, but is still bright.
Also, don't focus too much on the rated power of the amps. When I was auditioning the RX8 with the Marantz PM15S2 and NAD C375Bee, the NAD felt alot less powerful even though on paper it had more power.
Have fun finding what works/sounds best for you