From what I've read, go with the Hsu from your above choices. One person on Audioreview said that for the really low notes the 350 wasn't enough, and I don't know enough about the SVS to give you input. I was just shopping for a sub in the same price range for a large space-20' x 18'. I ended up with a PV800 by Boston Acoustics, it was a demo and I got it cheap. You may want to check out the Boston subs as well, they go very deep, with no problems. I've been watchin LOTR and the room just shakes with the gain set to 5 of 10. I also like the sub's ability to reproduce music without being muddy (listening to Eagles and Allison Krause, both CD's have distinct mid-bass, mid and high features and the sub doesn't interfere with the details. It blends in with them and sounds accurate with the rest of the recording). Another nice feature on the Boston's is the Gain knob on the front of the sub. Also placement isn't so tricky because it is down fireing with two ports. This seems to be the way to go if placement is limited, as it was in my case.
Good luck -Adam.
