My guess is that you have Raymarine instruments unless the previous owner has changed them, so you’ll need a raymarine autopilot if you want it to interface with your existing instruments. Older Raymarine intruments work on Seatalk network and later ones on SeatalkNG (Next Generation). You’ll need to find out which you have. The two work in a completely different way and are wholly incompatible with each other. If your instruments are SeatalkNG, then you are likely to be able to buy a compatible Raymarine autopilot off the shelf. If your intruments work on the older Seatalk network, then you might be lucky to find a working secondhand one on Ebay.