Please note the following about the copyright of the I-Metrics CMS.
The I-Metrics CMS was created by Mark Samios owner of asymmetrics.com. The I-Metrics CMS is released under the GNU/GPL license its details can be found here.You are free to remove the Asymmetric Software copyright notices from the webfront and the back end of the I-Metrics CMS template themes released by Asymmetrics.
The osCommerce copyright of the template web-front can also be removed. The osCommerce copyright of the back end (Administrator template) cannot be removed and it is subject to the copyright policy of the osCommerce details can be found here.
The template of the stock package was created by the freewebsitetemplates.com and removal is subject to their policy here. You will likely use your own template theme and therefore you have the right to remove all copyright notices from the webfront once you use another template.