First form fields conditinally choose next form, and next form submits all

HI....thanks again for such a great plugin! It's complex enough that I'm not sure how to do this..

I'd like to create a "mini" form with simple fields that determine the next form available.
1. User fills out small form with name, email, and chooses a product type from a dropdown
2. When they click submit, a new page is displayed that contains an image at the top (put in page) with the gravity form underneath (I'll just have the gravity form in the page so it all shows up correctly.)
3. The basic data is already prepopulated (name, email, product type) and then the user has to fill out the rest of the new form fields and click submit for it all to be submitted as a entry.

The UI is small form as a sidebar widget which will pass them to the final form (a page) for submission.

I understand how to make both forms, but I don't understand:

1. How to create a conditional on the first form (based on the product dropdown) which will redirect them to the correct page and also bring the basic data over to the final form.

Here's a screenshot of how it would behave:

http://cloud.uxdrx.com/1a050p1o0L23342K0c3h

Can you give me some advice on how I'd configure the first form so it correctly selects the second form and passes the data? I can set up both forms but I don't understand how to make it all work together using Gravity Forms.