I use Rythmik subs and can absolutely second the recommendation, but I'd also think hard about the SVS dual SB-1000 offer. A pair of sealed SVS subs with 12" drivers at $950 is probably a great way to maximize your chances of getting great sound, because A) SVS makes a very highly regarded product and B) dual subs offer a lot of placement flexibility (which really improves your chances of smooth, well integrated bass response).
Good luck
Good luck