perhaps this can help you to do it : http://www.jroller.com/a4j/entry/richfaces_calendar_component_shared_calendar
Like the shared Calendar, you can do a shared suggestBox.
in this case you can change you input into a kind of inplaceinput... when clicling on the cell, you put the suggestbox and the focus in it...
Once i had a lot of modal with just YES / NO
I have use the seam componant <s:decorate> with <ui:param>
i think it's can help you