With respect to your question about wire -- yes, you can use high end wire with Elizabeth's switch idea. Most high end speaker wire comes terminated with spade lugs, so just make sure that the switch you buy can accommodate the size of spades on your wire.
Do you have an extra line level output on one of your amps and an extra line level input on the other? If so, you can connect them at the line level, assuming they are close enough together.
Do you have an extra line level output on one of your amps and an extra line level input on the other? If so, you can connect them at the line level, assuming they are close enough together.