If you are wanting to stay in 12's, and money is no object, git the Eclipse T's, should give the w7 a runn for it's money! If you go with a 15 and money is no object go with Eclipse 15, or 18 T Pro. Just realised that you have the 1000/1, that amp isn't really big enough to push a T Pro. it would do fine on the Eclipse T though.
What kind of enclosure are you currently using ? The adire or Resonant Engineering Stuff would be cool. Elemental Designs, Kove Audio Armagedon...
Id Max is a great sub, but it isn't going to hit harder than the JL. In all honesty, all these subs in 12" form are so close to one another that in their optimal boxes you won't hear a huge difference besides the SQ. If you want more SPL, you'll need either more subs, a more SPL inclined sub like a Digital Designs sub in a ported box, or a larger (15") sub.