I am in a similar jam. I found an amp that matches my speakers, which simply was correct vs wrong compared to other amps I tried. It is weird that it is balanced Levinson proceeded by single ended Lamm preamp. I have heard the all Levinson amplification with my speakers, but prefer the tone of my current preamp. Other may prefer the opposite or just dislike it all. I am sure better could be had, but that's always the story.
Is system synergy worth having matched components?
What have been differences you have noticed in listening to amps and preamps from different manufacturer's together compared to a combo from the same manufacturer? I love my current setup of an Odyssey Audio Khartago plus amplifier and Aric Audio Unlimited all tube preamp. It sounds great to me. But am I doing myself a disservice by not even hearing the Odyssey Candela or Tempest preamp with the Khartago?