Magento – Magento add stock qty in backend new order creation

I was wondering how we could add a stock value in the 'backend new order creation' … see image below

What we see now is that we enter an order, but in the next step are warned that ther is no stock … so why not add the stock value as a column. Also we would very much like to filter on configurable products.

I was looking at app/code/core/Mage/Adminhtml/Block/Sales/Order/Create/Search/Grid.php

and wanted to add this code

if (Mage::helper('catalog')->isModuleEnabled('Mage_CatalogInventory')) {
    $this->addColumn('qty',
        array(
            'header'=> Mage::helper('catalog')->__('Qty'),
            'width' => '30px',
            'type'  => 'number',
            'index' => 'qty',
    ));
}

and the field itself in collection

 protected function _prepareCollection()
    {
        $attributes = Mage::getSingleton('catalog/config')->getProductAttributes();
        /* @var $collection Mage_Catalog_Model_Resource_Product_Collection */
        $collection = Mage::getModel('catalog/product')->getCollection();
        $collection
            ->setStore($this->getStore())
            ->addAttributeToSelect($attributes)
            ->addAttributeToSelect('sku')
            ->addStoreFilter()
            ->addAttributeToFilter('type_id', array_keys(
                Mage::getConfig()->getNode('adminhtml/sales/order/create/available_product_types')->asArray()
            ))
            ->addAttributeToSelect('gift_message_available');

        Mage::getSingleton('catalog/product_status')->addSaleableFilterToCollection($collection);

        if (Mage::helper('catalog')->isModuleEnabled('Mage_CatalogInventory')) {
            $collection->joinField('qty',
                'cataloginventory/stock_item',
                'qty',
                'product_id=entity_id',
                '{{table}}.stock_id=1',
                'left');
        }

but now the problems is that the 'order quantity' (most right column in image) is also called qty … and now they are conflicting. Question: How would I get the stock qty as 'alternate name' and show it?

And could we also easily add configurable/simple product selector?