Get collection with ordered quantities for admin grid

Question

I added a custom grid in admin panel which shows all the Best seller product collections. (configurable products). The admin grid has the following columns:

entity_id     product_name    sku      ordered_qty

I am getting the Best seller product collection by using Mage::getResourceModel('reports/product_collection'); but while filling the admin grid, I am changing the product collection to related to catalog product collection. as shown below:

protected function _prepareCollection()
{
    $from = /* some date */;
    $to = /* some date */;

    $collection = Mage::getResourceModel('reports/product_collection')
        ->addAttributeToSelect('*')
        ->setStoreId($storeId)
        ->addOrderedQty($from, $to)

    $common_ids = array();

    foreach($collection as $product) {
        $common_ids[] = $product->getId();
    }

    $collection = Mage::getResourceModel('catalog/product_collection')
        ->addFieldToFilter('entity_id', $common_ids)
        ->addAttributeToSelect('*')
        ->addAttributeToSort('created_at', 'desc');
    $this->setCollection($collection);
    parent::_prepareCollection();
    return $this;
}

As you can see in the above code, I am getting the product collection twice because the "reports/product_collection" is not filling the admin grid. So, I did "catalog/product_collection" again to the collection which is filling the admin grid.

But "catalog/product_collection" is not filling the column ordered_qty because the ordered_qty column values are being prepared by "reports/product_collection".

How should I get the values for ordered_qty ?