Where do I put Gravity Form Registration for Protected Content?

I'd like to use Gravity Forms for my new user registration, but I'm not sure where to put it to integrate with Protected Content. I have the form redirecting to the memberships page so they can sign up for a membership level in Premium Content after registering as a user on the site, but if I put it on the registration page (that is linked to Premium Content in settings), the memberships for Protected Content still show up underneath the form (even after removing the shortcode). I could hide that with CSS, but would that break the registration for Premium Content? Also, this registration page is the one that is linked to in the login page, so it would be best to put the gravity form there. Is there a parameter I can pass to Premium Content from the gravity form to tell it which membership to add the user to instead of showing the "Sign Up" buttons, since I already have a button on my gravity form?

Also, if I do use Gravity Forms for my registration page, it doesn't make sense for the "Change" link under the "Your Memberships" in the account page to link to the registration page. Shouldn't this link to the "memberships" page?

Gravity Forms on Registration Page
"Change" link on Account Page