A – Z menu on a Page, for a long list of content items

Hello,
On a page on my website, I have a long, alphabetical list of the names of companies. Rather than have visitors scroll down the list, I would rather display an A-Z list horizontally across the top of the page’s content section, so that the visitor can click on, for example, “G” and see a list of the companies whose names start with “G”.

Even better, the name of the company would also be a link to that company’s website.

Even better, I could insert product names/links under that company’s name, so that the visitor could go directly to that company’s webpage about a specific product.

I have seen something like this on other websites, but cannot find the correct ways to search for WP plugins that might be used, or for other creative ways to use existing functionality.

Thanks in advance for any tips!