Hi,
I'm one of creators of this project Network District.
We have modified our system to pledge. We created the pledge at 1€ "My Pledge". Others pledges will be deleted but we can't as long as there are backers.
With "My Pledge", you can choose all the buildings you want in SILVER version or GOLD version. You just need to download a Excel file which calculate the price of the pledge you want.
All instructions are described in our KS presentation.
Best regards !