Have you tried speaking with the folks over @ SVS? They have a selection wizard that lets you input details about your room, gear etc and will then make recommendations. You can then speak to the people @ SVS via e-mail or phone. I did this a year or so ago and had a good conversation with SVS. I didn't go with any SVS subs due to multiple system changes but they were cool to talk to.
Best of luck
Best of luck