The GFC500 is a 2 axis Pitch/Roll autopilot with electonic pitch trim as an option and requires that the Garmin G5 EFIS is installed in the aircraft. For a full list of supported aircraft – refer to the Garmin official website.
The Garmin GNS430(W) has been the standard COM/NAV/GPS navigator for a couple of decades and may be found in many GA aircraft. However some think that the screen size of the GNS430 and also GTN650 is a little to small and there is not enough room for the large Garmin GTN750. In these cases the Avidyne IFD540 (Garmin GNS530 plug/play replacement) may be an option as seen in the picture below. If you have an Ipad you can download a Garmin and/or Avidyne simulator from the Apple Store free of charge.