Ajax based task list based on mockup.

I need Ajax based task list/agile project management tool for internal use. I will provide complete front end design (mockups, some html pages and clear guidelines) as well as database model. These need to be turned into functioning, debugged web application by competent web developer.
I can send full specification and mockups to interested bidders via private message. The aim is to get version 1.0 with basic functionality and then to continue adding more features later. I prefer to work with fixed budget payable when product is delivered.
Some of the most important things version 1.0 should contain:

• Ability to create project, list, task, comment
• Ability to add “child” tasks to parent task (up to three levels)
• Ability to set/change due date and tag to the task
• Ability to add and change owner, status, type, value and effort of the task
• Filter and sort the contents of the list
• Prioritize task by moving it up and down the list with drag and drop
• Move task from one list to another with drag and drop (when 2 lists are on the same page)
• Virtual lists (views) based on criteria (ex. tasks that belong to user in all projects)
• Upload file attachment to the task/comment.
• Edit task and task properties “in place” (click on task and start writing, click on name to change etc.)
• Enter time spent working on the task
• Login and log out from the application

Remarks:
• Technology: ASP.NET MVC with heavy use of AJAX for front end. Backend: MS SQL server database.
• Support for modern browsers only (IE 8 and up, FF 5 or up, CSS3)
• Aim for minimal payload for AJAX calls and fast and responsive interface.
• Application will be multilingual at one point it should be developed with that in mind.