Easy Joomla Virtuemart Module Development

I would like to create another Top-Ten Product module for Virtuemart. In front end, The module displays like the Top-Ten Product module but I would like to have control in the backend. I can change the top-ten product order and arrange the position manually from the module manager in backend. Ideally the backend should have a product drop down menu for each position that I can choose what product for each positions. However, I am happy to hear for better idea on the backend control. If is possible, I would like this module can display and arrange more than 10 products. So it could be Top-Twenty or Top-Thirty. Let me know if you have any question.