Is there a WordPress plugin that will allow me to switch outside widgets depending on the post or page?
Yes, use Beaver Builder Themer.
Beaver Themer lets you create layouts for archive pages, template an entire post type, 404 and search pages, and create parts like headers and footers. Field connections allow you to connect your layouts to the data inside each type of template.
Theme templates allow you to create layouts for things like your blog archive, CPTs, WooCommmerce Products, and your 404 page.
Theme parts let you create partial layouts like headers and footers and display them on all or just some of the pages on your site.
Field connections let you plug your theme templates and parts into the underlying data in each page or post.
Take your archive and blog pages to the next level with full control over how each post in a list or grid gets displayed.
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I use it on all of my websites. Check it out. It’s awesome!
If you need help with this, I’m available for hire. Contact me at firstname.lastname@example.org