It is possible to merge Joomla and osCommerce together using JFusion. Before I had found this product Virtuemart was well on the way to being set up to Goenergin's needs. Virtuemart handles variations on stock much better, for example different sizes of a product. You have the choice of using stock control or not.
The site and contents are now easily managed by the site's owner thanks to Joomla CMS (Content Management System).
The site is no longer online.