Alter existing open source component Joomla or whatever for inventory management

I need someone to make some alterations to either Virtuemart or HikaShop, or whatever you feel comfortable using, however it needs to be web-based and open source, Drupal, Word press etc. The backend of the joomla deployment will be used for inventory management. Check out: [login to view URL] How it should function: Each product we sell is made up of component parts - eg: Butterfly 1 uses parts number a, b and c Unicorn 3 uses 2 x parts number a, 1 x part b, and 3 of part c I also want to be able to run a consolidated report that will give me a output of all the part numbers used across all orders. eg: We sell 2 Butterflies and 3 Unicorns so the report should show Part A: 8 Part B: 6 Part C: 11 I also want to be able to import sales data from a CSV source (offline sales) and be able to include these sales as part of consolidated reporting on part levels.