Broadband in Northern Cape

I've been approached by an organisation with many distributed offices in the Northern Cape. They currently spend a great deal of time and money travelling between these offices for meetings. They are now looking into video conferencing as an alternative...

Can anyone here tell me what are the best options for them in terms of connectivity? My understanding is that 3G currently has a higher dispersion than ADSL outside of the major centres, but it's still very localised. Looking at Vodacom's coverage map, EDGE seems to paint a large part of the canvas, but would it support videoconferencing? Finally, VSAT should have coverage everywhere, but it's damn expensive and the high latency could be an issue...

Any experiences I could draw on?

The only time I ever setup video conferencing was a while ago and we used ISDN lines.

2 ISDN Lines at each office and it worked great.
Not cheap though.....

It does seem that ISDN is the best solution. I was hoping that it might also double as an effective Internet strategy, and I suppose that ISDN is already heaps better than dial-up (but still suffers from the per-minute cost burden).

What additional hardware did you need to get videoconferencing working through ISDN then? Were you using it for one-to-one conversations or for a meeting environment?

Thanks for your suggestions.

ISDN is an option but costly, have you checked to see it ADSL is an option it the towns possibly.