My company is a well-funded, incredibly niche technical startup.
You have received good advice but I would also ask what is the goal of your PR efforts? Is it to drive awareness, gain leads, etc? Before beginning your outreach it's important to understand what you want to accomplish. This in turn will help you to craft outreach that matches your goals. You get journalists to write about you by telling them succinctly why they should care. Why would they and by extension their readers care about your story? Go beyond gathering target publications and names to understanding those you are targeting. Get to know them and not only their beat but their preferences. In addition, don't limit your outreach to trying to get journalists to write about you, offer content. Bylined articles are a wonderful way to establish thought leadership.