Starting a station, but behind a 'wall'

[RobPalm]

Hi there

I'm a newbie (and I realise how annoying they can be!), but here goes:

I run a small online community in Australia and we wish to introduce a weekly 'member only' internet radio show. We'll broadcast for an hour on a Friday morning.

It's likely to be a small - 50 max - audience to begin with, rising to up to 2,000 listeners within a year or so. The program would be me interviewing experts (by phone or skype) with listeners able to ask questions and join in via online chat (listeners will NOT join by voice, just by online chat).

Ideally we'll have a little 'listen in' widget that will reside within the membership area of our site that hopefully may include a chat window also. If this latter element is too tricky, we can run chat via Twitter.

So we're not wanting to attract a wider audience and it's important we keep the player behind our membership wall.

I'm darned if I know where to start. All the various services I see assume we're looking for an audience...we're not.

Any advice gratefully received.

Thanks

Rob