Customize Pro Sites sign up page

I'm directing new users to wp-signup.php to sign up for a new site through Pro Sites. I am not offering a free option. Is there a way for them to see the pricing prior to setting up their account, getting the email confirmation, and then having to come back to see the prices?

Also, can I disable the "just a username" radio button, so they just sign up for the site? I'm basically just looking for a simple process for the user to sign up and pay for their new site.