Hi, Any 8 ohm speaker will do, I think the output is about 15 watts. Speakers are not that critical as long as they are fairly sensitive and are good quality. I hope this helps. Regards Anthony.
PS. I speak from experience as I have built many speakers (infinite baffle,transmission lines, underfloor loaded and full range ribbons, the biggest over 7 ft high). The ribbons are my favourite speakers.
