Hi Alex,
If it needs to be kept private, then don't put it on a public server. Stated differently, if it would be disastrous for a competitor to get the info in the podcast, then keep it off any publicly accessible server.
If this communication is strategic for your client, and they are already shelling out the bucks for satellite distribution, then I would encourage them to redirect those funds and efforts to internal podcasting. Each of the outlets could connect via VPN to pickup the podcast. If you're not familiar with VPN (Virtual Private Network), it's basically an encrypted tunnel into a private network.
If the outlets are spread across time zones, they could possibly be configured to check during specific windows of time to spread it out a bit. This is where a podcatcher that is a little more configurable than iTunes would probably be worth deploying. Juice (formerly iPodder) looks pretty decent. It appears to have a scheduler built into it.
Compare the cost of the satellite versus adding bandwidth and VPN. There may be more uses for the VPN than just fetching podcasts, which could be a selling point. It's hard to tell without knowing much more than what you've posted. I understand that you probably can't post much more than what you have already. :)
Best of luck! Let us know what you end up doing!
Tony Gettig
http://www.gettig.net
