Amplifier and Speaker A/B switcher

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.

Thanks @8th-note ! I contacted them for a quote. I hope they are not too expensive.

decware makes a rather nice one for reasonable cost. not sure if there is a wait time though.

ZSB | DECWARE (decwareproducts.com)

Will checkout Decware too thanks @glennewdick !