Wow... I feel stupid... got the rear deck speakers out, 'cabinets' altered and speakers mounted (Phoenix Gold Xenon all the way around, as well as subs and amps)
Just have to modify the rear deck itself to fit the larger speakers, alter the original grille to cover mounting screws, and run wiring for the amp... next comes the front sets (I think these'll be the hard ones) and the deck.
Woohoo!