Add a/b switch? How to run 2nd pair of speakers?

I've got speakers in both my living room (main system) and kitchen. I used to have an integrated that had an a/b switch so it was no problem playing both or either sets of speakers.

Now I have moved up in the world and purchased a Rogue Tempest Magnum integrated which obviously does not have an a/b switch.

What are my options to keep my kitchen speakers running? I do not want to set up a seperate system. But, I've heard piggy-backing the speaker terminals degrades the sound.

Does adding a seperate a/b switch effect sonics negatively?
Where might I get one and what is a good brand?

Any ideas? Thanks very much.
I have the same problem, as my old Soundcraftsman amp had this feature, but my new McCormack doesn't, and I have electrostatic headphones that require an extra set of speaker terminals. I've been told that going to a speaker selector box, even an expensive one, will degrade the sound, so I'll probably have to blow off these headphones and get some new ones. Anyway, not much help here, but maybe someone with speaker selector box experience can add input.
Adcom, Bryston and Parasound all make Selector boxes. Audio Advisor carries the Adcom and Parasound. I have no idea as to the sonic affects of each of these units and would be curious myself. If you really want control over the quality of the component you could probably easily (and cheaply) build your own selector box. PartsExpress should have everything you need.
Another option is to add a small second power amp to your setup and either split the pre-amp output with a Y-adapter or, as in the case of the McCormack, use your second set of pre-outs to go to the second amp.

If you look around on the used sites you can probably find a small power amp good enough for kitchen speakers for less than the price of a switch box that's high-enough quality to keep from degrading the sound of the whole system. I got a nice little used Yamaha amp for $85 at a local dealer and it works very nicely