Lesson plans and discussion points from the film "Amistad" are covered in the book 'Reel to Real' (Vol. 2, No. 3), Augsburg, 1998, 9780687214334 (out of print) - copies may be still found on-line.
I've used other 'Reel to Real' books and would recommend them in general. Hope this helps,
You might want to check out the video "Amistad Rising" from United Church of Christ Resources 800-537-3394. They might have other child-specific resources, too. They used to have an Amistad Sunday every year.
Also there is a recreation of the ship "La Amistad" which is a floating classroom. I know they have a site on the internet, although I no longer have the address.
The address for the floating Amistad ship is http://www.amistadcommitteeinc.org/
Our church housed, educated and funded the return of the people from Sierra Leon that were on the Amistad. Check out our website from more historical background; http://www.firstchurch1652.org...n-historical-society
I believe next year is the 175th anniversary. I might just borrow your great idea and do a lesson for the church school kids on the anniversary.