it would depend on if the same engine is used in each gauge, plus you would need to find someone to marry them together. usually switching amongst product lines with gauges will not work unless it is a like engine IE 900ace to 900ace or 2 stroke for 2 stroke of same vintage. also the control system may be different, the smart gauges have more control buttons than our standard gauges do so that they can be manipulated. im not sure if the gps seadoo gauge has a joystick but odds are that it has something to change, zoom, etc. where ours do not.
anything is possible however, just have to be willing to put in the time. its probably easier to get a garmin or a tablet with a mount anyway, plus the gps imaging is much better and easier to operate on those units.
steve