Custom query or implementing an association

Hi Folks!

I have an requirement to fetch data from multiple Business Objects (BOs). I am thinking of following approach:

Create a Custom BO with a Custom query...implement the query to fetch data from both BOs.

Kindly suggest if this is feasible or suggest another approach to fetch data from 2 BOs ( they have no standard association between them ).

Eg.Get Business Partners which have no Sales order.

Regards,

Thank you!