My room size is very close to yours and is heavily furnished with carpet. I currently have the Tannoy X6TF speakers driven by an NAD Masters M32 integrated amp. I can't complain, however if I had to do it over I would choose the Focal Kanta One Speakers and probably replace the Masters M32 with the new NAD M66 Pre-amp and the Masters M23 amplifier.
Anyway if I were you go with Focal especially if you are using a tube amp. Be prepared to be blown away by the sound whether high or low volume.
I don't know your budget or which Tannoy speakers you are looking at. The Focal Kanta One Speakers aren't exactly cheap about $8000 a pair and an additional $1499 for the stands.