XNA Platformer extension

I have worked up an extension of the XNA platformer kit in XNA 4.0. I would like someone who can implement some of the following features. 1. Stock Physics replaced with Farseer or Box 2D 2. Sloped Tiles for the player and enemies to run up/down with CORRECT collision 3. Enemy and player Knockback (for when enemy attacks player or Player attacks enemy) 3. Inventory Screen 4. Character Selection screen for up to 4 players 4. Ropeshot or Grapple hook 5. Chain together multiple attacks. Again, I have the base code. You can use mine or your own, it does not matter. I just want it to work and BE WELL COMMENTED. I will be taking the project over again and NEED to be able to see what the programmer did and how to extend it. I only want to hear from XNA programmers. If you know C# but not game programming, trust me, you cannot do this in the time I want done.