Hi Guillaume,
In addition to the wealth of knowledge in the Data Services documentation (especially in the Administrators guide in the Migration Basics section) - here are a couple of Wiki's that should help you with this process as well and how to set it up:
http://wiki.sdn.sap.com/wiki/x/-II_E
http://wiki.sdn.sap.com/wiki/x/RYM_E
They explain how to port jobs from one environment to the next as well as information about the Central Repository and setting up different configurations in order to port things more easily.
There is no need to somehow cluster the production/test data services boxes.
Thanks,
Denise