Hi @treyfrancisco!
I like Paperform, personally. You can do something like this, where you display a dynamic success page, using fields from the form:

It’s not a page you can save and then link to, though. It would be good for a preview but not necessarily for people other than the submitter to see.
I actually worked on a little side project this week where I used Paperform for recording the data, then I used Zapier to create a page on a WordPress website. Because I knew what the page URL would be, based on the fields in the form, I could then redirect the submitter to that page. I added a delay of about 12 seconds, to give the Zap time to do its thing. I created a custom 404 page on the site, too, in case the person gets there and it hasn’t been made yet. It tells them to refresh and the page should be there.
Here’s a sped up version to show you the flow. The person submits the form, I show a custom “success” page that feels like it’s loading the next page. There’s an “error” but refreshing then brings up the right page (the Zap has finished doing its magic).

I’m not overly familiar with Formstack Docs, but I know that Paperform also has the ability to create PDFs, which you can then email or use in Zaps. You could find a way to embed that PDF somewhere.
Hope that’s given you some ideas!
What an amazing response. Thank you so much, I am digesting it and doing further research now.
Just a cool little demo, too. Nice work.