Can I get a little guidance? My Clarion marine amp died after 15 years and I'm shopping for a replacement. Here are my must-haves: [LIST=1] [*]4 channels [*]speaker-level inputs [*]variable high-pass filter [/LIST] My head unit is a Clarion GR10BT. It has a subwoofer preamp output to my my bridged 2-channel amp. So, I only need 4 channels on this amp, My front speakers are rated 100W peak. The rear speakers are 160W peak. What is the highest wattage 4ch amp that I should consider?