Faster mp4 download for swf game (streaming?)

I'm looking for some advice on speeding up the mp4 content download for my swf game file when played in a browser. I have been using progressive download but have found that it really drags with HD. I've never tried this but I would like to find a streaming option; I gave wowza a shot but it seems that they do not fully serve swf. Any recommendations on how to improve my video download speed would be greatly appreciated, or even the name of a multimedia server for streaming that hosts swfs.

Thank you!