Joomla Community Builder register/login plugin

I need Joomla Community Builder plugin with the functionality similar to what can be seen after clicking "Post Project" on freelancer.com, i.e.: 1. possibility to choose one of two options: "New user" or "Returning User" and - according to the choice - appropriate fields appear, 2. form has additional fields, e.g. "Project name" and "Describe your project in detail", 3. after submitting the form user is to be logged in or registered (according to his previous choice) and (if the user is successfully logged in or registered) additional fields (mentioned in p. 2) are written into the database (this I will handle myself) or the user gets the form back with an error (if something was filled incorrectly), 4. the plugin has to be compatible with Joomla 2.5, Community Builder 1.8.1 and CB Profile Pro 4. [Optional] ajax login (like on freelancer.com - user is automaticly logged in after filling the username and password fields). (sorry for the previous project with higher budget - it was created by mistake)