I’m looking for an application that 1)  has a shopping cart that provides integration with a payment processing service (preferably PayPal), 2) manages user access to areas of the site on a subscription basis and 3) can trigger document delivery (or send a protected link via e-mail) to customers by using the PayPal IPN feature.  Preferred solution would be PHP/MySQL based.  The closest thing that I have found is dotWidget for PayPal http://www.hotscripts.com/Detailed/15265.html (only $29 ), which has both the payment processing integration and document delivery features AND which gets high user reviews.  I can’t tell if it has the ability to manage subscriptions.  Does anyone have any experience with this application?  I suppose that I could have a separate solution for subscription management, but an integrated approach would be preferable.  I had such good luck with this board the first time around.   Thanks in advance for your suggestions!!!

www.oscommerce.com should be good. I use it at www.soccergrip.com and I think it probably has everything you need. Most of all, it's free!