Hi, I'm designing a game for web browsers. I've got multiple professional game artists, and musicians working on the project but I'm lacking experience in best practices to block hackers from causing havoc to my systems. After I launch the game users will expect it to remain up 24/7 and I'm the only developer supporting it.

I'm expecting 5 thousand users with up to 700 active at one time. I could use help determining what server bandwidth I'd need.

Not sure if I should break off player chat and music sessions to separate servers.