Earmark Car Audio in Addison does amazing work. I'd definently look them up for any custom car audio work you need done. My next system I am putting in my car is going to be done up there even though it is a long drive from where I live.
I am looking for the Soundstream SS-10R or SS-12 series subwoofers. Preferably a pair of them, however singles work too.
Also I am looking for the Soundstream 10.0 class A amplifer, the solid chrome one.