You can still buy Scala 400 software from Software Hut in the U.S.
Working Amigas of various sorts can be bought on ebay.
I found this describing a Scala500:
http://amiga.emugaming.com/bundles/scalawork500.htmlLooks like basicly an Amiga CD32 running Scala presentation in a kiosk footprint...you can do as much with any Amiga and Scala 400 or even Scala 300 (which came as a hard drive installed (no floppy/CD) bundle on some systems).
I'm not sure how Scala will help you as a new video/film producer though.