Hey Robert,
This is Max, one of the Gurus here at Shopify.
I did some digging around for apps that might enable that functionality for you. It looks like there isn't any that do both of the things that you mentioned above.
Something you may want to try is to use an app that can add a "sticker" to the product picture on the collections pages. An app that can do this is Product Sticker. This way you can use the Stock Reminder App in addition to Product Sticker. You would be able to have the sign up form on your product page and notify your customers that they can sign up from the collections pages.
You also might want to get this custom coded into your store if you don't find any app solutions that work for you. You could try getting a quote from one of our Shopify Experts.
Hope that helps :)
Max P | Shopify Guru