Where can I purchase Raymarine ST5000+ Autopilot control head?

I had a working Raymarine autopilot setup consisting of a ST5000 plus control head, Type 1 electric hydraulic steering actuator, rudder position sensor and ST600R remote. Unfortunately, thieves stole the ST5000plus. So I am looking for new old stock or a drop in replacement of some kind. I found that the ST6000 series moved the computer to a separate box and so it is no longer a drop in replacement.
Where can I buy one of these ST5000+ units or some later model that is compatible? If there is nothing that is a drop in replacement what would be the lowest cost solution to replace the stolen controller? A new control head + course control computer box? Would this interface to my type 1 hydraulic actuator? Would I still be able to use my existing Raymarine rudder position sensor and flux gate compass including my ST600R remote? - Thank you for helping out with any source for this discontinued component. - KyleO