Hi to the group, many owners have a second autopilot - on Amel 54 ferropilot - or have an autopilot as spare. How often did you have a failure and which part of ferropilot is needed ? Second complete installation with hydraulic , electronic needed ? Did anyone had a windpilot on the stern for the case if the ferropilot fails ?
the FURUNO pilot you have, with L&S hydraulic pump and strut is a very reliable system. If you want better, you should have a full second one installed.
Although I never tested it, I'm not sure a windpilot could handle an AMEL 54. Moreover, it will not be easy to install because of the bath platform and ladder (which is a safety equipment, in case of man-over-board).