How to get to know with attractive speakers who work for global famous companies?

I am now trying to connect Japan and other countries through holding webinars with attractive speakers from oversea. I searched on Google and found some speakers' agencies like "Big Speak.com" but I don't have so much budget. I don't expect top leaders or CEO, but just want to know some case studies and strategies at global famous companies (like GAFA, global retailers, Mcdonalds, etc...). I tried to find speakers at conferences' speakers page, and then made contacts via LinkedIn. But it is very tough to find. If you have some good idea to reach someone out, please let me know. Kind regards…