Which scrum project management tool to use?

I want to propose a scrum project management tool to the customer but not sure which one to recommend.

Need to find an evaluation criteria to select the right tool.

We have a distributed team (india & Aus)and the project will be executed in scrum of scrum mode (10 teams running parallel sprints and integrating)

I have some options like
Rally
Versionone
Scrumworks
Mingle
Xplanner
IceScrum

Appreciate your help.
-Kaushik