I just bought 4 MM651UM speakers for my new pontoon. I am pretty new to hooking all of this stuff up on a boat and am not sure where to go. Here is what I am thinking. I want to add a sub to these speakers as well as two outdoor ones that I can operate via a toggle switch for when I am off the boat. I want the outdoor speakers to be hooked through the switch so they are not on all the time. Any suggestions on what to do for a marine amp? Do I need two? How many speakers can I hook to one channel?