IDX Broker will replace the Search Bar on the front page. You will still need to use the AgentPress Listings plugin to add the Listings to the front page. You are also able to add IDX information to your listings pages.
Most also use the Communities Custom Post Types. It allows you to add information specific for your communities, and then you can also add IDX info to those pages.
So you can set up everything except the Search Bar on the home page, if you will be using IDX Broker.