Software/Script To Block SEO Bots (Like Majestic, Ahrefs)

Hi All I require a solution to block all link finding SEO bots via Htaccess file - I need to block all the main ones like Majestic, Ahrefs, and many others. As far as I am aware, the only way to block is by IP addresses through the Htaccess file. However if you already have a solution for this, then as long as it works, I don't care. If you don't have a solution already, then you will need to do your research and find a way we can block all these SEO bots, and leave only the ones like Google, Yahoo and Bing. After you have developed the script, I'll need a way to implement this on over 200 websites. So we may need a software, or a script that we can upload to each site, that fetches the solution from a central location. We will also need something I can add to all future sites created. I'm honestly not sure how someone would go about the above, but if you think you can achieve it (or already have) and are up for a challenge, message me! I will pay only after I have tried the solution and it works for me on multiple sites. So it must work before you get paid. As a gesture, I may be willing to give something for your time and effort if your team is unsuccessful. However, do not apply for this unless you are confident you can achieve it. And if you can achieve it, the reward will be good...trust me :-) If you have any questions, message me. Thank you