Guidance/advise for html5/ipad ebook system needed

one of my customers brings out small publications regularily, each available as pdf file. he would like to make those publications available * on his website as optimized html5 versions for ipad and other tablets * with an ipad app (maybe also android) that automatically downloads new issues, presenting and making available all current issues to the user. * and he would also like to add some multimedia elements like videos, zoomable images, etc. what i need for now is not a final code or product that i can use, but rather some guidance/advise what would be the best way to build a solution according to my client's needs. would it be a good idea so convert the pdfs to html5, make them available on the client's website and build a custom ipad app that shows the current issues and automatically checks for updates? what tools (preferrably open source) could best be used? and are there any systems already available that basically do what i need? please post a bid for this consultation with some infos about your background and let me know if you need any further information to place your bid.