Change order of signup process on Protected Content

I have found that i can use Gravity Forms (or any other WP form plugin) to create a user then redirect them to the Memberships page, when they click an item they are then made a member.

So the process currently is:

Signup link -> Register -> Select Membership -> Done

The client has requested that the process be

Select Membership -> Register -> Done

Is there anything i can do with field population in the Register form or is the current process vital to the functionality of the plugin?