Anyone add these gauges after the fact? Im very interested in adding it to my Optimax pro xs 150. After my cousin's issue with brand X boat and his Mercury 200 Pro XS alarm sounding all the time, you never knew whether it was fuel, low oil, no oil, fuel restriction, or overheating. My old System check gauges would tell me what the fault was. I'd like to add one, but its difficult to figure out which one to add. I know my motor has the hook up for it, and my GPS is NMEA 2000 compatible. I know I would need a NMEA 2000 bus to set up (those parts are easy to idenfiy), but there are so many part numbers for gauges, Im not sure which one to order.. My dealer quoted me $1700 but I think that's way high since you can get a gauge for around $500 bucks and its plug and play. I only want to replace 1 of the 2 4" round gauges. Thanks in advance Todd