Advice on equipment

I own the Klipsch Forte III and two different models of ZU Audio speakers.

They would work well with any of your compoients.

Klipsch announced an upgrade for the Forte III to Forte IV,  you could maybe find a pair of III around your budget and do the mod when funds allow.  

Forte III is a very capable speaker.  

I would sell the Carver, keep the Fisher 800C (will be great with efficient speakers),

keep the Sony, enough power for less efficient speakers now, use in a second system later. It can drive two sets of speakers (another space?). I use my transistor Receiver in my Shop/Garage system, each space it's own speakers. A, B or A+B.

Keep look for a great deal on used efficient speakers while saving for new Klipsch if used concerns you.

With 30 watts per channel from the Fisher and assume your other receivers produce at least 30 watts it would be over 90dB sound pressure at 3 meters with 87dB sensitive speakers. That is loud. I am not fond of Klipsch unless they are Cornwall or Khorns. If you must have high sensitive speakers buy Cornwall and never look back. No problem with the Cornwall competing with $3K and higher cost new speakers.

I would sell the Fisher and keep the Carver. As for efficient speakers consider Tekton: