Speakers for SET 8 Watt 300B system?

I run a pair of Zu Essence speakers (16 ohm, 100db efficiency) with my 9 watt Manley amplifiers. The sound presentation is very vivid, palpable and immediate. It took me some time to arrive at the high-efficiency SET sound, but I have no regrets. One of my Manley amps is on its way to the factory to replace a failed oil cap (the amps are 15 years old now) and my temporary replacement leaves me yearning for that SET realism.

I would give the new Zu Druids some serious consideration. They have gotten great reviews. I intend to replace my Essences, as good as they are, with the Druids this summer.

I run Coincident Frankenstein 300b mono blocks thru my Zu Druid V's and an Undertone sub with great results!

I'm driving a pair of Tekton Lore S's with an 8 watt KT66 Inspire amp built by Dennis Had. More than efficient enough.

Quads quads quads

I think you want to select highly sensitive speakers. Then listen to whatever is available for audition close to you. Perhaps take your amp with you to the dealer.

Klipsch, Audio Note, Tannoy come to mind.