Advice please - Correct switch and how to wire it up (##SOLVED - Thanks Bub and G :-) ##)

 
My 33 year-old Pioneer hi-fi amplifier has finally given up the ghost, but I have another amplifier all ready to go.
 
The old amp has two sets of loudspeaker outputs and a built in OFF-A-B three-way switch (the 'Off' position is for when using headphones). I've got two pairs of hi-fi speakers, and it's great being able to switch the output between the two.
 
However, my new amp only has one set of loudspeaker outputs.
 
I want to build a little switch box that works pretty much the same as the Pioneer's switch, but actually a little simpler, as I don't require an 'Off' position.
 
So:

• Does anyone know what type of switch I need to accomplish this?
• How do I wire up the 12 different cables into this switch?

 
Here's a rough schematic to illustrate what I'm after:
 
 

 
 
 
 
Many thanks in advance of any help and advice
 
 

This shows you how to make a super cheap one.

http://www.instructables.com/id/AB-Switch-on-the-Cheap/

The unit that ohgrant has suggested is not suitable. That is designed for low level RCA line level signals NOT speaker voltages and currents. 

The article that Bub referred to is also not suitable. That is a crappy switch feeding miniature headphone outputs.

Switching speaker voltages and currents requires a different approach.  The device however you have suggested is much more suitable. Don't mess around with building it as the unit you are looking at is cheap and will do the job perfectly.

I can see why it's now "solved".