Video Membership Site

Does anybody know the best solution for streaming videos on membership sites?

I’m asking because I’m planning my to have a video membership site with online lessons. I need to find out some information about average sizes of good quailty videos, and ways to stream them. Is it good to use web hosting like hostgator, what about amazon s3 and it’s pricing? This is crusial to see if it’s worth to even start building such a service..If anybody has some experince with video membership sites or has one, I’ll be grateful for any kind of feedback here.