You can have not enough, but there's pretty much no such thing as too much sub for a room.
Size might be up there:
http://www.powersoundaudio.com/products/xs15 (sealed but 15" driver will get you better output)
Also an HSU design:
http://outlawaudio.com/products/lfmEX.html or the Plus...
It may be different for a different sub, but the corner is a fine starting point. The PB2000 could replace your table... :) The PB1000 won't fill a large room, but if space is a concern and the room isn't too big the PB1000 is a good option.
From HSU, the VTF-3 would be a closer competitor...
Since music is a lower priority, I'd agree that the vented one would likely be a better choice. Sealed subs will still hit the lows, just not with the same authority of a low tuned vented sub. Since I listen to a lot of music, I tend to prefer sealed, but I've owned plenty of vented subs as...