Yes, a GSD would be perfect for you, except that they do not get along with other dogs. Lady doesn't really dig much, and she hates other dogs. Actually, I think you could get them to get along, and since the GSD is the one coming into Jake's territory, and the GSD doesn't really have anything to defend. They also can be very "playful", and defensive about their toys and stuff. Here's the search results from Google that you can take a look at to see some other traits and stuff.

http://aolsearch.aol.com/dirsearch.a...hepherd%20Dogs

Hope that helps, I love searching for stuff!