Best Buy sells Precision Acoustic speakers. They look rather similar to Quest ( not sure if they are the same company), that Future Shop sells. I haven't heard the PA sub, but I have a Quest sub, however, I have heard the sound quality is similar.
The Quest sub is better than nothing and originally I thought it sounded pretty good, but it fades rather quickly playing DVDs. I only paid $150 for the 10 inch-150 watt sub.
I would have to say that, it would be better to save a bit more and buy a better sub as I wound up doing anyway. I got an athena 12 inch, 800 watt BASH amplifier sub for $399. If you check Future Shop for web sales, you sometimes can pick up a bargan. That is if you buy from the big box stores. If you go to a dedicated HIFI shop, you probably can pick up even better bargains, with better quality components.
Give it a listen first before you lay any cash down and then decide if it will " do the job".