You don't say where you are located, but in the UK there are many sailmakers who will quote you for sails in response to an email. They usually have a form on their websites that you can fill in with the measurements of your boat and what sort of sail you would like and they will quote you. They may well have made sails for the same model in the past and be able to advise on different types of sail.
The original sail dimensions will be in the handbook that comes with the boat from Bavaria, but it will only give you area not the dimensions. However if you Google Bavaria 36 sail dimensions you will get a number of sites that give the dimensions that you can use to check your own boat against.