Data Feed Plugin to work with Wordpress Template - open to bidding

Hello, We have a mainframe, which real estate properties are placed into. We are trying to develop a plugin, whereby, we can draw the property listings from the online mainframe, and have it automatically put up on a website (wordpress theme or the likes) using an agents username/password credentials to stream the data (needs to update every 30 minutes - just in case there are new property listings). Thank you, message me if you need more information, Best Wishes, R.