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.