Well they do have bi-amp possibilities. I actuall inquired with Harman about an active crossover but didn't get much help. The manual mentions that identical signals need to be sent to both upper and lower speaker jacks but may mean identical gain.
Otherwise it seems like a great speaker to bi-amp with an active crossover. High powered solid state is relatively cheap for the bottom and would put your tubes to good use on the top.
Would be very interested as to what you decide. BTW, I'm very interested in a pair of Salon 2s but like you have questions about the amps.