I'm going to note that most will keep the form data in a DATABASE and be able to call such forms and data back from the DATABASE.
Storing the PDF will likely incur storage bloat and likely why you may not find a ready solution.
Bob
I have a web application which uses forms (users fill out) that I would like to then generate into PDFs (from html). Does anyone know of any web service providers that provide this feature on their servers or have any experience with a product that does this that they particularly liked?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic