-> 2 PB1000 would out gun a single PB2000.
90% of people are satisfied with home theater in a box by LG or SONY... Most of those who think that sucks will think a BOSE home theater system is amazing... Then the few that the bose does not impress are impressed with say a POLK 505... Then the last maybe 5% that are not satisfied with that require an SVS, rhythmic, HSU, other internet direct, then maybe 1% require a DIY multiple 18"
Logic -> Out of over 900 people that bought the polk 505, almost 800 gave it a perfect score... That means 89% of people that bought the 505 are perfectly happy with it...
That being said, you need to determine just how crazy you want to go, and how much money/time/effort you wish to put into your system.
I don't think anyone can go wrong with most of the ID or DIY options.
I will say though if you want a purchase that will DEF last a LONG time, just get the SVS. It may have a bit less output, but will sound just as good or better, and last almost forever. But again, you can't go wrong... Pick your trade off.
Hope this helps.