Im i college student in his last year, in order to get the degree i must do a final project, so i decided to work in an application which could make/check money transfers and payments between two users from the same bank instead the classic credit card process in a e-shopping open source solution (credit cards arent too popular in my country), im looking to extend its functionality (magento) via java. Im learning about EBJ 3.0 and web services but im not quite sure where to start or even if its the right technology for the project's vision.

I would aprecciate any conceptual or bibliographical help in relation with the projects goals

Thank you very much