Customizing the Registration Page (Multisite)

Hi there --

I'd like to customize the registration page for my Wordpress Network, however am a little stumped.

I searched the community/stackoverflow and couldn't find anything that works with my setup.

I'd like it to work with my WPMU plugins (e.g. Choose Site Title, Description, Password, and Theme) on signup.

Does anybody have any experience with editing this page?

Thanks,
Al