yeah man glad you posted before it was too late.. youll be happy about gettin somethin else im sure..
and about 6-700 isnt too bad but it depends on what you want.. after you tell us what youre looking for and how much space you have we can make recommendations..
also, if you havent already.. check out..
resonant engineering
digital designs
adire audio
image dynamics
ascendant audio
jl audio
elemental designs
there are dozens of awesome companies that you may not know much about that are in most cases much better than mainstream subs (fosgate, audiobahn, kicker, etc)
but these are some of the most common (theyre the ones ive been looking at forever anyways) and those companies should give you a start