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!

Okay, funny story with this subject.  It's all true though.   Years ago, my wife, now ex, had three cats.  They would run around behind my speakers and disconnect the banana plugs.  I had satellites and two subwoofers on each side, so there were a lot of banana jacks and plugs.  I got tired of missing some of my music every time I turned it on, so I ended up getting locking banana plugs.  Pricey at 30$ a pop in 1985 money but it cured the problem of cats yanking the jacks out.  So, in a roundabout, kinda sorta way, expensive banana jacks made all the difference in my system. 

I used them up until a month ago when I switched the subwoofers and sub amplifiers over to 5/16's crimped and soldered terminal lugs and #12 AWG dual quad speaker cables.