Integrating New Blog Templates with Gravity Forms

I decided to use Gravity forms and the "User Registration Add On" to create new sites in my multisite network instead of the default wp-signup.php page that WordPress creates. This works great so far. It gives me much more control over the fields as well as the ability to embed the form on any page.

Here's my dilemma though:

I'm unable to show the templates I've created in New Blog Templates. Is there a way to integrate this? Or is there any other solutions you can think of?

Selecting a template on my network is definitely a necessity...