Connector system between 12 GAUGE speaker wires

Aloha again!
After the highly appreciated top suggestions here:

https://forum.audiogon.com/discussions/scratchy-sound-from-tweeter
I am now stuck with: 

how to put a connector system between the last 3 foot of 12 GAUGE speaker wires that run inside the speaker stands to 8 GAUGE wire to connect to amp.
I find plenty of banana connectors but NO female ones. I do not like to use flimsy RCA connectors.
What can I use to quickly connect and de-connect my speaker stands (on rolls to move aside if in the way)

I wonder if there is any solid system out there?
Can I pair banana connectors with kind of binding posts?
Any suggeestions?

MahaloPuu