What you purchase is your decision on what meets your needs.
Photostory Deluxe is the minimum I would recommend - Easy does not have a lot of functionality and is basic in what it can do.
Moving up from Photostory is Movie Edit Pro, prosumer level, with much more capability and features. Video Pro X is the top product in the Magix range and is aimed at the pro/broadcast level of use.
Trial versions are available for these - try them to see if they do what you require, however do note that theya re limited in functionality, video format import and export, and not all features are available.