Binding Post?

The binding post for earth ground or the binding post for the speaker output?

For the speaker output, use a heavy gold plated one and solder the internal wires with a high lead content solder.  Avoid silver solder since the chances of getting gold embrittlement is much greater with the high tin content of silver solder. 

Binding post for earth, just get a good one with lots of copper or brass in it.  It is just a drain for leakage current so no audio signal flows through it.  Or, at least, it shouldn't!

https://www.parts-express.com/WBT-0735W-Topline-Fully-Insulated-Binding-Post-White-093-557?quantity=1&AID=13715689&PID=8280252&SID=ff6748b9b41b17e275902b708c204a4e&cjevent=5a5f906697f511ed80dd04e60a82b821&utm_source=CJ&utm_campaign=8280252

I think KLEI makes the only low mass binding posts that I am familiar with but I’ve gone lower mass. To truly go low mass you have to abandon the attachment for lugs. I use BFA style "banana" plugs. they aren’t really banana and make a much better connection.

Cardas is the antithesis of low mass.  that is what inspired me to make my own.

Let me know if you’re interested in how I make my own.

Jerry