I have a similar size room, but no treatment. I ended up with Neat Acoustics Petite. If you are considering a British style speaker, I would give them a try. I have driven them with an LTA Z10 and an Orchid Audio GAN amp. They have some interesting floor standers.
I've had the Omega Super Alnico's. I enjoyed them for Jazz. For me, they definitely needed a sub.
Sonus Faber or Serblins are on my list to try at some point.