Specific funnel for some products

Hi, I’d like to set a specific journey for some specific products.
As I’m offering a free trial, I’d like the customer to have this journey:
1. clicks on “free trial”
2. inserts name and email, clicks activate
3. order completed

I thought that this was the right plugin, but what I can’t figure how to do, is to keep the same checkout procedure for all other products.

I can see that I can activate the direct checkout for just some products, but I can’t set up a custom checkout page: the settings I change in teh settings page affect the standard checkout page.

The page I need help with: [log in to see the link]