Just to clarify I am not a horn guy.This seriously limits your choice of spkrs.
Adding on to Team212's list & David's AN recommend'n:
Zu
Klipsch (Horn / Scala)
JBL (vintage)
OTOH, I am not sure about the AN driving Tannoy Canterbury. I listened to this combo and, while "nice" the sound of the whole was unconvincing given the stellar specs of the parts...
IMO you definitely need a product that offers at least ~100dB / 1 watt / 1 m or better AND definitely need to try it out. That is at least half the fun, btw!
After all, a 100dB spkr will give you ~88dB at listening position for 1 watt (assuming you're listening at 12 ft away); you'll run out of steam soon over 94dB. And this is for a nonexistent, series resistance /totally flat impedance speaker! While this is plenty loud, remember that 30dB dynamics are very common in music... which brings you down to 94-30= ~64dB