Image Download

Hi Guys,
i am working on a site where i want people to download images for free…i upload the images via the Media Libary, then i call it up inside a post or a page…what i want is to add a download link under the image so when people click on it a dialog box promting them to save the image would appear, i dont want a case where the download link would link directly to the image thereby opeining it up. Also would like a download counter next to the download link like what we have on the WordPress.org download pages, like This has been downloaded 20304 times..

Any help or advice as to how to go about this my project…

Thanks in advance