No one actually knows how to lculate what speaker cable they need

Nice choices.  Let us know.  I saw those same spades and they should works nicely. If to big or bulky to fit, then you can buy spade to banana high quality connectors.  

Do you have a link to those adaptors? I don’t think I came across any.
Nevermind actually, I googled. I might already have some bananas that’ll work.

My plan is to bend the spades back by 45 degrees to give myself additional clearance if needed. it’ll be interesting.

Cardas and other quality companies make them.  Here is a very nice one from Cardas. 

http://cardas.com/cab.php

b4icu,
I will share my impression on this exchange. I paid $25k for 2 pair after discount.
The Goldmund amp have 2 male BNC output for speaker connections. Anybody know where I can buy the female connectors. I plan to connect the 6AWG cable by this connection if I can source the female connectors. Many thanks to all.

Mr. khiak

The connectors you call BNC are not BNC!
GOLDMUND TELOS 600 : http://www.audiounion.jp/ct/detail/used/95826/
Or the last page of your GOLDMUND TELOS 600 RTFM.
BNC: https://www.iitk.ac.in/ibc/BNC.pdf
It looks more like an enlarge (not STD size, but very large) TNC.
GOLDMUND would be a good place to start with. I don't like this "unique" approach. However, the TELOS 600 have also 4 ordinary binding posts.
I am kind of confused...how did you connect the GOLDMUND TELOS 600 with your speakers till now?