The Garmin GPSmap 478 also has NMEA 0183 interface, and comes with the fancy cable that SD mentions above. I like that it is a GPS *AND* a usable Chartplotter. I believe that the Garmin 276C, 376C, 278, and 378 would work too... Look here for detail: Garmin. We'll Take You There.®
I'm not sure if the negative line goofiness applies to these units.