[C320-list] Cockpit Speakers suggestions

[Magnuson's Ragtime]

I want to add a sound system and have made my interior hardware selections.  I want to install cockpit speakers, and think I would like to mount them under the stern seats as opposed to cutting holes in the fiberglass.  I would appreciate any suggestions Pro and Con, and suggestions for wire routing.  The GPS antenna has been fished up through the center of the stern rail, and fished out through a hole in the railing to the antenna pod, It looks very neat, but perhaps a factory install.  Has anyone run speaker wiring through the stern rail? Any suggestions for protecting speaker wiring run along the rail surface?

Thanks,
Gary Magnuson #205