the diablo 1000 is I believe, $499, David and Bill are great people to deal with. You can check out their section on here or their website (it is under construction right now though)
Sub wise...most anything can be made to sound good with the proper box. I agree do some research...see what subs people say are better in a certain box, size, cost, power handleing, .... then make a decision.. what ever you decide should be from your own opinion....