RSS Product Feed Expert for Pet Website

We are looking to generate an RSS feed that delivers updates when new Pets are added. We currently have a C.M.S. That allows the user to enter the various breeds and other information of the pets for sale. We want to extend that to allow people to sign up to be notified everytime new pets are added. The feed should be capable of being delivered to eMail, and it should include Thumbnail Images (which we already create when we enter the pets). It should also be able to be subscribed to like a normal RSS Feed Further, we will want to be able to convert the RSS feed to html, so that people can place a simple code snippet into their website that will allow them to display the feed on their websites. New feeds should be generated when the user selects the Pets to be published, just like a new blog feed "PUBLISH-UPDATES" function.