Silverstripe form redirection question

As far as I can see, there are two options here:

A: Programmatically Create a Page

1.       Render a page when the form is successfully completed (and email had been sent)
2.       Page should not be included in the sitetree, or be accessible by anything other than a successful form submission – typing the URL should redirect back to the contact page.

B: Limit Functionality of a Sitetree Page

1.       Create a new page type for form success
2.       Page should not be accessible via menus, search or by typing the URL – typing in the URL should redirect back to the contact page.

(A)   Has the advantage of possibly hooking into the routing rules meaning we can utilise a single class for rendering multiple ‘thank you’ pages without things getting messy in the routing rules.
(B)   Has the advantage of content being editable in the same way as other standard pages.

I’m happy to go with either, but it depends on the complexity of the solutions using Silverstripe...