Which CMS is easy to use DotNetNuke or Umbraco. Further can we integrate our existing project with it?

Question

We are in the process of implementing a CMS for our project which currently extensively uses asp.net master pages and css. Also the application is data-driven and controls like gridview and listview are used. After a little search we zeroed on two CMS dotnetnuke and umbraco. Now my question is:

1. Which one of the two CMS is best suited and easy to use?
2. Do they support integration of existing code and UI's

Please provide links for further reference.

Thanks in advance.