Digital Window Display for estate agent

We need a program to run a digital window display for the window of an Estate Agent (real estate) office in full screen. We need ability to create multiple tamplates for the layout of a main picture and The templates should fit an HD screen (1920 * 1080px) The templates could be in HTML /css format with space to add info, ie: <div id="price">[[price]]</div> or something similar. So we could generate this ourselves easily. The data will be retreived via an Http connection possibly returned in XML format. We have a framework setup linked to the database of properties, so I can create the asp.net service to return requested informaton to the digital display. The computer running the displays will be on the internet so can request updates whenever it needs them. But will need some form of caching as the photos may take some time to download and we don't want delays. So it will request all the properties and photos and then update every half an hour? Should have the ability to retreive information in multiple languages, including Russian. The language will be chosen randomly, so this is also possible that the ASP.NET web service could deal with this. There will be 4 shows running simultaniously, 1 per screen. So the user selects the show from a list that is supplied by the asp.net system. Please ask any questions that you have and give me your suggestions on how this could be acheived. a .net windows application may work with direct access to SQL, but for security reasons I prefer the http: approach.