Doug. Thanks for your kind words. As you are aware I am a Sonus Faber fan for their sound characteristics. The same ones that you identified as your own. So from that perspective they are a great match sonically. Given the tier they are in, they should provide a great boost in sound quality across the board once they are broken in… at least 125 hours. Remember this if you buy them… it is so easy to get really excited and start drawing conclusions too soon. Also, I would definitely not feel bad about liking them because they look good. The nice thing about Sonus is they sound fantastic and look as good. You get much less grief from your partner as well.
I am firmly in the camp of starting an upgrade cycle with speakers. Even if it is years before you can upgrade your amplification you can enjoy much better sound now, and another big jump later.
The Arcam has enough power. Sonus are not power hungry, although when powered by solid state amps they can benefit from more power. I power my Amatis with 70 wpc (although it is tube) and I can turn them up far louder than I can stand without loss of dynamics. Sonus has a house sound, natural and musical… it is distinct as you pointed out.
Anyway, sounds like a great choice.