Should I keep my boat speakers connect to the amp or put them to my head unit?

I have a Clarion XMD1 head unit on my boat right now. I just bought a CMD6 head unit since my old one was having problems. I was thinking of switching the boat speakers from the amp to the new head unit to take some heat off my Panasonic amp. I have 2 amps which are a Kenwood 150 RMS x 2, and a Panasonic 600 x 6 amp. I have 4 boat speakers, 2 tower speakers and 3 subwoofers on my boat. Right now I have a box of 2 subs on the Kenwood Amp and everything else on the Panasonic Amp. The Panasonic amp kept getting too hott and turning off. I disconnected the sub that is under the drivers cockpit from the Panasonic and it seems to work better. I was thinking with this new Clarion CMD6 radio that it would be better to connect the boat speakers directly to the head unit and connect the subwoofer back on the Panasonic.I was wondering if I should do that? Also my box that has 2 Pioneer IMP subs started going bad, its not hitting like it use to so I might replace that any suggestions on what sub would be good to replace them with? And what tower speakers are good? Also do you know if the CMD6 should fit right in to the spot where the old XMD1? I know its alot of questions and I also don't make alot of money but don't want to have to replace everything in a year. Thanks for your input.