Welcome to the forum, Annie.
I can vouch for SVS subs. I have two SB-1000's and a pretty old pair of PB12-NSD's, and they've always performed reliably in 2 channel and home theatre use.
If you go to the SVS website's "Outlet" section, you can find a bit of a break on the price of a new unit, also 5% off when you buy a pair. I find them to be a great bang-for-the-buck option. Their customer service is also first-rate.
The only suggestion I can make is that if you really need to feel the "rumble" of the lowest bass notes and you play movies loud, you might consider going up to the SB-2000 or even 3000. They'll play a little deeper AND a little louder.