Eh, it's done - I guess I wouldn't try to squeeze the high performance of a Maserati out of a Ford Focus, so I should stop worrying about doing just this for my audio system.
It might take a little while to get there, but I'll keep you guys posted as I go along, and post some pics of the new setup at some point.
Patience is a virtue...
SVS-PB12 or better, at this point I'm not going to fool around with anything less. That's my final decision - thanks greatly to everyone here for the advice and the assortment of options.