Amplifier and Speaker A/B switcher

I've been using a switch made by Beresford of England. It allows me to switch between my mono block tube amps and my SS amp to the same set of speakers. Works fine and even has resistance added to protect your tube amp if left on when not switched in. I think Declare offers a similar switch.

J.Chip

I use an amplifier switch made by Dodocus in Germany (dodocus.de). It is super high quality. As of a couple years ago it cost $460. Well worth it.

I wonder if this one would suffice, good price: 

https://www.ebay.com/itm/402999423706

OP,

Switching the banana plugs is certainly a good way to assure no impact  on sound.

The higher resolution your system, the more prone you are to hear a switch box. Given your equipment, I think a high end audio switch box, would be indiscernible in your system and be more convenient. 

Maple Tree Audio makes custom built router switches. They call these Engineered to Order (ETO) Routers. I have one that does 4 in, 1 out (RCA) and it's nice looking and well built. You tell them what you want and they get back to you with a quote. You can even choose the type of wood for the side panels. Great company to deal with and made in America.