I need to be able to edit a PDF (with dynmic database form and bubbling feature)

I am wondering what the best approach for this would be.

Here's my problem at hand:

Hopefully this can be done on a web page (ASP.Net)...

1) Allow user to open a previously created PDF

2) when the user click son the document, I create a bubble\Oval where they clicked

3)  this click will open a form (specific to that click) and allow the user to enter data (maybe 5 fields) attached to a databse

4)  if the user clicks another area, it replicates the same steps listed above

5)  user can then save the document

6)  if they re-open that doc again, it should show all the bubbles\ovals create on page and when each bubble\oval is clicked, it displays that form with the data previously entered

What is the best approach to take here with Adobe products?

Buy acrobat along with the acrobat sdk?  I will install this on a customer's iis box.  Not sure how licensing occurs here with multiple users etc...

Thanks,

Tim