Hardware and performance

Hi!

I have a question about how to design a system for multiple physical sites.
I have to use Windows-based computers and WAMP. So *NIX is out of the question.
Different physical sites mean sites with low bandwidth and some sites with high bandwith, and a central site.
I'm looking for a solution that users in the low bandwidth sites can watch the videos as well as the others.
As far as I know, moodle has three key components: the web interface, a mysql database and a folder called "moodledata".
My questions are:
- how does a client acquire the selected stream video? My thinking is: a client log in the web freontend, asks for a video. The serverpicks it, then the client start the download _through the web interface server_. So the bottleneck is the bandwidth between the web interface server and the client. Am I right? If not, then how?
- is there a performace issue, if I put all web interface servers into a virtual environment? Windows NLB will be still working?
- how can i syncronise the moodle databases between different servers with mysql? Is there a built-in solution?

Thanks in advance
Regards
NG