[Plugin: Gravity Forms] How to do this?

I have a selection box with 3000 options. Its a list with contacts. I copied list from csv, where i also have a phone number city etc.
Here is what i need to do:

When user choose a contact in a form, text fields (city, phone number etc.) will fill automatically. I know i can do this with conditional but there is 3000 contacts so i need to do import this in some way.