I'm planning a wordpress website which will use buddyPress, and really important to it will be a list that the user can maintain of their favourite items. Users will need to be able to move the rows up and down to change the ranking of the items, and be able to share their lists.

I know this is going to take a fair bit of customization, but I wondered if any WP experts out there had some ideas of how best to create this functionality? would it be better to modify an existing plugin? (not that I can find any), or if not, what kind of JS/PHP coding would be required to create this kind of plugin?