Redmine

I have to create a dashboard which would access Redmine project data. This dashboard will be a consolidation of project data viz. delivery date, % completion, manager, start date, Headcount, bug count and a progress chart for each project.

Redmine hierarchy that I have to follow:
Project-> Release version-> Sprint -> User Stories -> Task -> Bug

I plan to use Redmine REST API (C#) to solve this problem. I am using this API and can find methods to list all issues associated with a project.

Does anyone about API's which would further extend this Redmine API and help me getting the desired information from Redmine?

Thanks, Pranjal