How much money do you have? For around 3000 bucks you could buy a bose and it has a dual zone speaker set up ( you can listen to different things, in different places). I have the Lifestyle 28 and it does this. go to
www.bose.com
or you could simply go to the store and buy an amp or splitter, 2 extra speakers and then run them outside (make sure you get outdoor speakers of course) and then you could turn off your inside speakers and leave the outside ones on and the play it that way.
but if you are wanting to impress the ladies... buy a bose...