The list of open source eCommerce software we can supply or host, install, configure, and support (at the time of writing) is as follows :-

Title	Version	Description	Rating
Magento	1.3.1	Magento is a new professional open-source eCommerce solution offering unprecedented flexibility and control.
Drupal	6.15	An extremely flexible and extendible CMS system whose powerful capabilities extend to eCommerce
OpenX	2.8.0	OpenX is an open-source ad server, with an integrated banner management interface and tracking system for gathering statistics.
osCommerce	2.2rc2a	osCommerce is the leading Open Source online shop e-commerce solution.
PHPCoin	v1.6.1	The phpCOIN (Clients, Order, Invoices, and Notes) package was designed for small to medium sized webhosting resellers.
Simple Invoices	20080629	Simple Invoices is a simple, community developed, free/open source, web-based invoicing system.
SugarCRM	5.2.0e	A powerful open-source package for managing customer relationships.
Vtiger CRM	5.0.4	A free, full-featured, 100% Open Source CRM software ideal for small and medium businesses
ZenCart	1.3.8	Zen Cart is a free, user-friendly, open source shopping cart system.

If there is a title that is missing off this list we might be able to install it for you.