I built my own. Extremely happy with it. It was fairly expensive, but considering my boat is in the water year round in Alaska, and if I'm not on the boat I'm 360 to 700 miles away, it is well worth it.
Cellular internet modem
Cheap D-link cameras
Custom built PLC system - 6 float sensors, high and low temp alarms, engine monitoring, fuel metering, generator start/stop and timer run, encrypted security cable for dingy and outboards, door sensors, and remote controlled outlets for heaters, heat tape, or whatever. (I can turn on the heat in the shoulder season when I am about 3 hours away). Any alarm will sound a local strobe and siren and send us emails and texts. In place now since 2013, each summer I add a few more features to it. Gotta know your way around electrical and how to program PLC's though, or pay someone who does.
In addition to that, I also have a SPOT HUG satellite based unit that will send texts and emails for up to four dry contacts, I have it wired as a redundant notifier for high water, security, and shore power alarms.
Although I trust the PLC 100%, my critical high bilge pump is still wired direct to battery with a heavy duty float switch. The other four pumps are controlled by the PLC and connected float switches (I set them to run an additional 30 seconds once the bilge float goes off to get it as dry as possible). I can log into via my iphone or computer from anywhere in the world and make adjustments, turn on/off heat or freezer, manually run pumps, disable/enable security, etc.. In the highly unlikely event of PLC issues, the relay box I built has three way Hand/Off/Auto switches to each pump, going to hand will run them manually, and a button on the PLC screen will switch control from the PLC with "de-bounce" and "continue to run once clear" timers to direct control of the pumps via the floats, bypassing the PLC.