Spec me a server

Hi everyone

Started a streaming site offering free streaming a few months back and since then it has taken off.

We are now planning on moving to dedocated servers as "the cloud" is not big enough for us and the bandwidth is very overpriced.

We are working on getting a 1gbps port server that will be able to streaming 900-1000 users at one time.

There wont be that many on it for a while but we are hosting events that would be getting 700 users, plus the already 100 or so on the site we need to be able to take that amount of users.

We are also hositng about 1.5TB of videos for charitys and nonprofits so would also be having people watching them, but not very many.

What spec server would I need for this?

Thanks.

PS, lowest spec and an ideal spec suestions would be great

Jack,