It my experience, it's all about networking. I have multiple fortune 500 clients as a consultant and all of those clients came from referrals. I think your best

It my experience, it's all about networking. I have multiple fortune 500 clients as a consultant and all of those clients came from referrals. I think your best bet is to speak with people in the private and public sector about your idea (i.e. would they be willing to pay $$ if you had a working model) and gauge interest from there. You'd be surprised how many people are willing to talk shop in a more casual setting (meetups, conferences, etc...)