Wordpress customization

I need a slight modification made to Wordpress. I have an animal website, and I want to have extra fields on the 'create/edit' post page so I can add extra information that will be found in the sidebar, I have a lot of pages so using a 'widget' that only displays on certain pages as the list of pages will be massive. For an example see the right side of this animal page (I want something like the box titled 'Bandicoot Facts': [login to view URL] Some things to note: - It must be setup in a way so that I can decide on where it is placed on ever page via a widget. The widget won't have any options it will only be there so I can place it either above or below another widget. - The type of information I want to have in the sidebar will change so I will need the ability to 'rename and remove/add' the fields - as with the example there should be a hover effect - please see the example and hover over 'Kingdom' for example. - Please see the attached screen shot of the layout of the site at the moment - the new feature must sit like a widget. Any questions please ask before bidding. Thanks Ricky