We're making what is essentially a site that contains multiple pages that each contain multiple panels. Each panel is going to contain different information and a different layout. They want to be able to add X number of panels onto each page, and they want to be able to use different panels in whatever order they so choose. .

So I was thinking that I'd create a document type per panel type. I would then create the actual panel content in a sub folder that is not part of the main website. Since the panels are interchangeable, I was thinking that I'd add them similar to how one would add widgets to a page, (aka using a Multi-Node Tree Picker).

I will then create a content page, and select which panels I want to display. I'd have a user control / partial layout that reads the values from the MNTP and gets the content from those panels. 

The issue that I can't wrap my head around yet, is whether or not I can grab the template for the different panels so that I can display the content of each panel appropriately and dynamically.

Did any of that make any sense?

I guess an example of this would be https://www.greendot.com/greendot where each of the main navigation items was it's own 'panel'. Each 'panel' looks different and contains completley different layouts.