We have several plugin's/extensions for the these various carts but we're having issues. We are not getting very good support from the developers who created them, so I need to find a company who's responsive and familiar with a variety of shopping carts.
These plugins/extensions are developed in PHP, MySQL, and they all tie into a single control panel developed on Yii Framework.
This would be an on-going maintenance contract on a "as needed basis". We also need the developer/s to update the extensions/plugins for new version releases for the carts.