In order to get your checkout setup like this you would need to do just a couple of things. You will need to apply the restrict access rule to your checkout page to ensure that users are logged in first.
Next you should remove the parts of the form that you do not need. You will also need to remove the corresponding validations for the fields you removed.
That is about it from the functionality point of view. The rest of it will just be to remove any values from the displays that you do not want to show.
This can be accomplished with a few steps but it is a custom implementation. If you need help getting this part developed you can try posting in the jobs forum to see if anyone is available.
