I have a client request a server to make online education movies playing to their members...
anybody can recommend which server company can host it?

what server spec. and software corresponding the requirment?

There are a lot of different companies out there .
Do they have a lot of members? What size are the movies?
How many hits do they expect to get?
Do all there members try and view the movies at one time (like for example in a school situation where a class is told to go watch movie Y) .
What format are the movies in (do they need any special software like real server)?
Are there viewers east coast or west coast or mix?
That being said what countrie(s) are there customers in?

4 dual xeon servers clustered. 2 DB server, 1 download server and 1 webserver :D :D

Specs could be as high as that and can be as low as a celeron 1.7.

Nobody can answer your questions until you answered demonmoo's.