You would be better off bringing two 120's on separate circuits. One to your rack, and one to your subwoofer. A third to your rack if you feel you need more than 800 watts per circuit. This will act a a signal isolator in itself and will help protect against ground loop issues between your equipment and subwoofer which usually is the biggest problem.
I use Tripp Lite Isobars. They come with US$200K and $500K warranty protection and provide signal isolation, as well.
I am not one for paying extra for line conditioning as most AV components come with good regulating power supplies already.
If you do the things above and you feel line conditioning is still necessary, then go for it.