Hi,
Well, I can see that their documentation is in Dutch. So I would recommend to have a Dutch developer work on that.
I would recommend to contact your local Joomla User Group to see who would be able to work on such integration.
With PHP skills, our developer documentation and their developer documentation, it should be possible for any developer to work on that. If it's someone related to a Joomla User Group, it's even better as they probably already know a lot about coding for Joomla.
