You're a lot better off using Flash if possible. You can get good quality and low file size with FLV format movies, and Flash player is installed on more computers than Quicktime.
I've never done it, but I'd assume you should use some JavaScript. I use something similar to this: UFO for embedding flash objects. It utilizes the DOM to detect and embed the flash. I would almost certainly think something similar can be used for Quicktime.
Yea, Flash is def your best bet. Check out http://www.whatisclear.com to see an example of some pseudo-streaming flash.
We used the Flash Comm server to accurately find your connection speed, then we served up an FLV formatted for your connection. We don't actually stream the file to you, its a progressive download.
We couldn't actually do the streaming because the Flash Comm server license's are based on a per-connection basis. In other words, if you want to have more than 150 people viewing your stream at once, expect to pay an exorbitant amount of money for the licenses (which are sold in packs of 150 for $4,500).
In the end, I had a horrible brand experience with Macromedia (before the buyout) and figured out the progressive downloading is usually better than streaming.