Try this one:
https://www.amazon.com/Niles-Black-FG00230-Speaker-Switching/dp/B00W4FN47K
It switchs input and output of 2 amplifiers, 600W rated, but only for single ended.
https://www.amazon.com/Niles-Black-FG00230-Speaker-Switching/dp/B00W4FN47K
It switchs input and output of 2 amplifiers, 600W rated, but only for single ended.