Who are some of elite sub woofers?

The problem with subs is it is impossible to get uniform, even and powerful deep bass with just one or even two subs. Also they cannot be located symmetrically the way the two main speakers are or you only make the inherent uneven response even worse. A minimum of three (and four is much better) located asymmetrically are required. The good news is using 4 allows them to be quite a bit smaller. The best solution seems to be here: http://www.audiokinesis.com/the-swarm-subwoofer-system-1.html

for music I like JL audio and Rel. Both would be a huge step up in quality. What is your budget and it is for just music or home theater too?

something with an active crossover is always nice.