Pro Sites - redirect after registration

Hallo,

How do I set up a redirect after a user has signed up for a 30 trial?

I would like to be able to do this for two reasons:

1. This final welcome screen can be the place I add tracking and conversion pixels.
2. Later I would like to be able to add upsells so I can then automatically show the users the next step in the sales process.

Thanks!
Justin