Connector system between 12 GAUGE speaker wires

Aloha again!
After the highly appreciated top suggestions here:
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?

The customary solution with plain old wire like that is to strip about a half an inch and twist the ends together.
Just get two double banana plugs per speaker. One connected to the speaker leads. The other to the longer length from your amp. Push them together to connect the two different lengths. Pull apart when you move each speaker. Easy!
The banana plugs I use allow them to be piggy-backed - one into the other.
Post removed 
Thank you all!The 12 gouge wire to the speakers go down through the sand filled speaker stand posts and come out at the bottom and right here I need the pull apart system.

How can I post a picture here to make more clear what I am not good to explain in words?

Another try:  
The  speaker wire is connected to the speaker port. This speaker wire runs now invisible down inside the speaker stand steel post.
It comes out of the steel pipe at the bottom of the speaker stand and here I have a foot length to play with and here it needs a solution to connect / dis-connect   it to the speaker wire that runs to the amp.
+ wire ---------- male  plug >>>     into   == female kind plug -----  to amp
- wire  ---------  male plug  >>>     into   == female kind plug -----  to amp

ieales, thank you so much for the link, this looks like my solution.2 of them and 8 banana plugs and I am good to go.
I hope that this project will not have a negative effect on the sound quality...but I can live with 5% less (:-)))

Thank you all again, I settled on the solution member ieales suggested and hope the order arrives soon and all will be good.

Happy listening!