Sonos doesn't make anything for outdoor installations, although there are ways to do it. The trick is in preventing moisture getting to it and making sure it doesn't overheat.
If the wires are fed to the house, the only thing you really need to make sure of is that the insulation isn't cracked, pinched & shorting, that there are no bad splices in the wires and they didn't feed one wire and split it between four speakers. Once this is done, use whatever speakers you like and put the amplifier/streaming device in a location that's safe for it and allows it to connect to the network. I always recommend hard wiring network devices because they work much better than if using WiFi.