Integration of property database XML feed

We are an estate agent based in France and have a large database of properties. We advertise our properties for sale on various property portals in the Uk & Ireland (e.g daft.ie, propertyfinder.com etc) to attract foreign buyers looking to buy an overseas property in our region in France. Currently we have to manually add each property individually to these web sites which is exceptionally time consuming. Our internal office property management system is a well known UK based system and provides an XML feed of our complete property listings. We are looking for someone to take this XML feed and link it into the XML feed of the property portals so all uploading and advertising of our properties will be automatic. All XML details and manuals can be provided for both our office property database system and the web portals. Please see enclosed examples.