If you've got a large room and you like tight bass and SPL's then how about putting two 10"er's in the room? Put one by the couch for the rumble effect. The SVS sight when talking about doubling up on subs estimates a 6db increase (seems a little optomistic to me, but I'm no expert). To keep to a reasonable budget you could go with two HSU STF-2's at $550 cdn a piece HSU Canada . I seem to recall from a previous thread BrenR mentioned there is a dealer in Winnipeg. If not, you can contact the HSU cdn distributor and ask for the nearest dealer. If nothing is close they may make you the same offer they made me when I was looking for a sub. They were very nice and said they'd ship it to me (Edmonton) for an extra $10.

You mentioned you were more comfortable with a manufacturer that has a long warrantee. I don;t think you'll do much better than HSU, the website states "Warranty: 7 years on the woofer, 2 years on the electronics, parts and labor included".

Happy research and shopping - Paul