bkoopers wrote
Is my idea of using the menus possible?
No, you would still have to author the menus using a DVD authoring program. And if it was long enough, you'd run into the limit for the size of the disk that can be used for menus.
As Jim says, PR alone won't do this. Encore, Adobe's DVD authoring program is End of Life and no longer included in a subscription. If you bought it in the past (a product that included PR CS6 for example, which included EN CS6) you can still use it. It is no longer for sale.
Encore's method for doing slideshows is described on page 122 here:
https://help.adobe.com/archive/en/encore/cs6/encore_reference.pdf
If you don't have a purchased copy of Encore, you need another authoring program. I assume others may have a slideshow function, but I do not know.
FYI, DVD (NTSC) is 720x480 and applies to slideshows. Blu-ray will look much better.