Personally I have the Weichers Front Upper Strut Brace in conjunction with the Eibach ARB kit, the Eibach kit was a big improvement over the standard bars and ading the ront upper brace stiffened the front end up even more, in my case I felt the car had a tendency to feel like the balance was switching front to rear through fast corners making me feel very uneasy. The above combination has completely negated this.
I'm adding the Eibach Pro Street S Kit in February so hoping for a pretty awesome ride and handling set up.
Not sure what differenc it would make on a sportwagon though, you'd probably end up with quite a few sqeaks from the dashboard as the car's chassis would flex differently on the road.