The Kicker KXM800.5 is the marine 5 chnl and is very close across the board power wise, to the zx700.5. Its class-d so way more efficient with a much smaller footprint. The KXM800.5 comes with its own mounting hardware and allen tool for the terminal setscrews.
i agree with David. Any extra steps to try and pinpoint a root failure will go a long way with the replacement amp.