Thanks for all the suggestions, so I'm going to do this in phases for the time being...
Phase 1...Install the 10" Sub and the M700/5 amp hooked up to the cabin speakers.
I'm going to look for a deal on tower speakers and when I do find them, I figure I can bridge channels 1-4 on the amp to provide power to the tower...should be easy to re-route the power. I'll also look for a deal on another amp to power the cockpit speakers once the tower speakers go up.
Appreciate the help here...supposed to be -28 here in the next couple of days...I think it's going to be a while until the ice melts on old Lake Minnetonka....argh!!!
Boat: Med Blue 2012 X2
Old MC: 1998 Maristar 225 VRS
Rig: 2009 Chevy Tahoe LTZ
He who dies with the most toys wins...I'm losing right now!!!