Hey Mavrey, I just bought this stock footage for a title sequence I'm doing for JDRF charity. I first tried to recreate it in Motion and it just isn't the same as having the high speed alpha channel footage.
Take a look at the demo footage and it looks like you can do what you're looking to do. http://www.digitaljuice.com/products/products.asp?pid=760
And I find Creative Cow forums a great source for Apple Motion Help.
Good Luck.