Need to add lists of prospect companies to an opportunity using the lightning filters

Greatings. In the past you did some salesforce customization for me and I wanted to talk to you about a new project. We help land developers find money from investors. We start a new opportunity for Land Developer 1 and then we need to search our database and find prospects to reach out to for this land developer. We want to be able to add the prospect list to the opportunity page so we can track where they are in the process (i.e. contacted, interested, not interested, no response). Can you help me to get something like this set up? If so how much will it cost. Sincerely, Eric Gins