Thanks @carlsbad and @mbolek . Those look interesting too!
@joshua43214 this is exactly why I've been going down this rabbit hole. I'm worried about the weight and stiffness of the cables too, and also managing what to do on the back of the Marantz with the small spring connections. Was thinking banana but I'm not changing out frequently, maybe I'll give spades another look. Fun to learn, thank you again everyone for all the good leads.