Four Speakers to a 2 Channel Amp

I am installing four tower speaker on a wakeboard tower on a my boat. Its a seaseaswil tempo. Most of the componets I am using are hand me downs and I was trying to figure out the best way to hook them up. The amp I will be using is a Pioneer PRSX720 Specs: 100W X 2 / 4 ohms 400W X 1 / 4 ohms Load Imp 1-8 ohms Speakers are ks60 PMS 65 W Peak Power 130W Impeadence 4 ohms I was trying to get advice on the best way to wire them up. I not the best with mobile audio and was wondering if it would be better to wire them in parallel or in series? If I should bridge the amp first or not. Any help would definitely be aprreciated. I realize this might not be the ideal amp but the wifey got me on a budget and there's not room to purchase another amp.