The woofer section and the horn sections of a La Scala are equal. Systems that cross over near the 400 to 500 Hz spectrum share equal amounts of power. Altec when James Lansing was working for them proved that. Now a horn is acoustically load the woofer, like an acoustic suspension box does, but not to as low of frequency. So bi amping is not really important in this case. Bi amping was developed to match drivers with different efficiencies. Why have a 500 watt operating full range coupled to speakers through a passive cross over, when a 250 watt amp on the bottom and a 50 watt amp on the top could do the same thing. Then when you realize the professional system might have 15 or 20 amps on the bottom and a much smaller number on top that bi-amping becomes economically advantageous. Musicians started experimenting as did home owners and they found they could use tube amps on top with SS amps on the bottom to get different sounds.
Amps with low damping factors are easily in influenced by the reactive load of the speaker, where SS amps with high damping factors are not. So its a process of match or mismatch and what ever sounds best to you. Then different amps just sound different. A Mac 2105 sounds different than a Crowm DC-300A or a Marantz from that period. BGW, Crest, QSC, all have different sounds. Personnally I much prefer Crowns Reference and PSA2 amps to the amps they build today, Mac amps 2105, 2505, sound different than todays 152 from earlier 202. But yet they don't. Mac has a certain signature even though there are other differences. Its like buying a Steinway piano. Big concert pianos should sound all the same, yet they don't. Some seem to have a faster action and response time, some are a bit bigger sound some a touch brighter, but yet all are easily recognized from a Baldwin or Buesendorfer.
The same goes for amps. Different tube amps will give you the widest change in voicing of a La Scala , but different SS amps will have a different but not as broad of change. Personally I would try a Mac 7200 on the bottom with the understanding Klipsch woofers don't like much more than 60 watts continuous. Every system I ever sold using split La Scalas, I had to pull the K-33 woofer and replace it with either a trimmed down 16 " Altec or Gauss woofer. The spider wires would fail every time, and I used 70HZ high pass filters of a crossover when crossing over to either MWMS klipsch boxes with Gauss or Altec woofers or Altec subs with dual 18 inch woofers.
A La Scala in a home environment is a very strong speaker, so maybe a smaller 7100 or 754 might make you happy. Even a little Crown DC 150 A would be a good match with your 275. But remember you are going to need a 400 HZ low-pass filter for the La Scala bottom section to interface the woofer with the horn using the passive Klipsch crossover. Removing the top passive Kipsch crossover section will open a real can of worms do to all the level matching going on between the horns and the woofer section.