I have a GRT EFIS with a Trio autopilot. I know a lot of you RV flyers have the autopilot coupled to a GPS for hands off approaches. Can someone provide a list of IFR GPS's or GPS/NAV units that will drive the autopilot and even shoot the missed approach? I know the NEW Garmin GTN's will but are there any other options other than a GTN or a 430,530 unit? Will a Garmin GNC 300XL shoot the approach and the missed? Any help with this is appreciated.