Well if its any consulation, I just setup an old vintage system using Duetta Sigs driven by a single KSA 250s A Krell 250 upgrade) driven directly by a Wadia 6 and the sound was phenomenal. I also have had Calipers in the past but never Stages. Due to a recent move I have been trying to decide what is going to work best in this new abode. Main room is 18w x 28d and has a massive vaulted ceiling in which the system would sit at a wall where the slope meets fortunately. (built in band shell!) After this Duetta run, I will haul in a pair of Divas and bi-amp them with the other 250. Hopefully they will not be too big and "load" the room. However I have seen some members systems here where the speakers seem bigger than the room!
I would try a KSA 150 with your Stage if you were to remain in the Krell lineup. I heard a friends setup that used one with Stages and it sounded fantastic...one here on AG for 1500 I think right now.