Data Source CE in Visual Composer

Hello Experts,

we are running on CE 7.2.

I wanted to read BPM  task details into a custom application or generate a report of who has claimed the task,currently being processed by whom  and the history of this information relating to every task in uwl.

I know that CE 7.3 offers BPM API's using which thiscan be accomplished.

However I have also read that Visual Composer can provide this solution.

I have the following queries:

1)what data source should be selectedif i choose to go with vc

jdbc BI template?  or BI....we do not have a Bw system in our landscape and our datasource is portal DB.

2)Does that mean BI usage type will  have to be installed alongwith BI jdbc connector..

3)what would be a more feasible solution ...upgrading  to 7.3 or installing the BI component. ( we need to perform only reporting activity as to with whom the task is currently pending  and ho had processed it in the past)