I've had many 300B amps, have FOUR now, and The Sophia 300B is excellent. Sorry, don't know about Wright's amps.
Hope it helps. We have K-horns as well, and I would strongly suggest the Heritage Crossover upgrade advertised here on Audiogon. We've performed many upgrades to our system, and for low-wattage amps, Dean's crossover was the most noticeable improvement we've experienced.
Others that I consider essential:
1) re-wiring with silver (you need 20ft.): dramatically improves the clarity, speed, and definition of the sound
2) dampening the horns with Dynamat or the like, which removes the shout effect, and helps to project the sound into the room.