Plugin development

I need a plugin developed for a magento store to integrate to channel advisor. The plugin must use a GUI in magento to map the data fields. This plugin will be used on multiple magento installations Our requirement is to get a plugin that be used on any magento installation that can connect to channel advisor and synchronize inventory, products, from channel advisor as its sole source of information. Then it needs to sync all order information to channel advisor for processing. All of this information needs to operate in a near real time environment. We manage many Magento stores on multiple servers, so the solution must be portable to be installed on any magento store and linked to any channel advisor account. The GUI to map the fields from one account to another should be easily configurable in a settings window within magento. API access will be provided to our channel advisor account upon request. A sample magento store will be provided to build the plugin on. This plugin and all code will be evaluated by our developers. An NDA is required for this project. My budget for this job :: 5k to 7 k INR Thanks, Abby