The title of the thread got me going. I thought you were taking all the Stereo Integrity out and putting in new drivers.
I see you want to compete with Chopz on SPL!
I think the two subs will fit back there with some creativity. I liked your set up before. I'm interested to see where you end up moving everything and placing another amp to power the extra sub. Any chance you want to buy my ST-850 XM II? lol
Edit: Actually I guess that ST-1000 would power both with no problem.