Usually the best way to do this is look around for sites that you think you would be a match for, and contact them directly. Most have a 'model for us' link at the bottom.
There are several studios who shoot in and around Western Europe, so you should have an easy time finding them. Also, you could just go out on your own and sign up to one of the amateur platforms. You have to take care of your own promotion, but it's easier than ever to get set up, and there are also agents you can sign on with who can take care of promotion and management for you.
Good luck!