Well, it all depends.
First you have to get yourself a fast server with huge bandwidth pipe.
If majority of your audience is in EU, I can recommend Leaseweb - since colenak is "file" streaming site and not live streaming site, I guess you are trying to do the same - go for something with large amount of RAM (16+)
and unmetered bandwidth.
Next, you don't need Flash Media Player as cledin suggested, as it is prolly an overkill at this stage. Mod_flv is enough, one random tutorial:
Code:
http://tperspective.blogspot.com/2009/02/apache-flv-streaming-done-right.html
SSD's are not needed, Linux kernel does a great job caching everything in RAM. Bandwidth wise, your calculations are: bitrate*1.30. This 1.3 is 30% overhead of network protocol. However, keep in mind
that this is borderline calculation, I would go with 40% just to be sure.
Leaseweb has some crazy bandwidth options, like paying 95% utilization and that kind of things - make sure you investigate everything before embarking on this project.