I want to embed new blog template in my custom plugin


I like the way New Blog Template gets embedded in the wp-signup.php page for allowing users to select the template for new site. Can you please tell me how can I embed the New Blog Template's same content as on wp-signup.php page to work with a custom template I am trying to write for our system, if possible?
I want to display the templates of New Blog Template, store the information in database in a custom table of my plugin and then invoke the wpmu_create_blog function at a later stage to create a new blog with the template selected.