Kind of like asking, "Chocolate, Vanilla, or Strawberry"!
You've listed a $2,000 KT-88 tube integrated, a $2,500 solid state amp that will require an undisclosed preamp, and a $5,000 solid state integrated.
The only one I'd choose is the Cayin, because I'm partial to tube amps. I'll just add that if you're seriously considering the Cayin, consider the A-70T instead of the A-88t. I've owned both and much prefer the A-70T. The fact that the 2.5x the cost Luxman is better is of no surprise or consequence to me as it's clearly outside my pay-grade!
You've listed a $2,000 KT-88 tube integrated, a $2,500 solid state amp that will require an undisclosed preamp, and a $5,000 solid state integrated.
The only one I'd choose is the Cayin, because I'm partial to tube amps. I'll just add that if you're seriously considering the Cayin, consider the A-70T instead of the A-88t. I've owned both and much prefer the A-70T. The fact that the 2.5x the cost Luxman is better is of no surprise or consequence to me as it's clearly outside my pay-grade!