We have already implemented a B2C Webshop for one of our customers (see http://frisiawebshop.easyplex.com). Now we need to implement this webshop (based on Magento) also for B2B purposes. The good thing is, that we can reuse the most functionality. It's more about adapting the sales process, changing some parts in Magento etc. Design and user interface specification are finished. The shop is connected to others systems via Web Services, but this is also implemented and can be reused.
We would set up everything you need. SVN access, a development server and access to our issue tracking (JIRA).
The reason why I need an expert is, that I have to implement and finish the project within March, which means I need a person, who knows what to do and how to implement features in Magento/php. Therefore it would be good if you could start already next week. Are you interested?