superimposing fireworks on sky

[luckyinkentucky]

The last scene of this movie im working on takes place on a hill above the highway tunnels. Its a dialogue, and behind the actors is a blank horizon. What I'd really love to do is add some fireworks to the sky ... I think my basic knowledge of aftereffects and finalcut would get me through with lots of tweaking, but does anyone have any tips? And more importantly, where can i get some stock footage of fireworks? Any possibility of downloading it for free? Thanks

[machead]

do you know anything about Alpha channels? I reccon you could do it with that.

[sn-films]

ArtBeats has a couple clips you may want to look at.

http://www.artbeats.com/prod/search....eworks&fm=&ct=

The full resolution clips will cost $$$, but you can look at the thumbnails for free.