Paul I dont think any of us on here really have a great deal of experiance with remote communications - perhaps that other "big" site that deals with camping / caravaning and 4x4ing might be a better place to start looking.
Though personally I think going into a few dealers that deal in this type of comms equipment might be a better option than getting "my brothers mates sisters husband used" type opinions you are likely to get on forums (particularly that other site previously implied...)
I did look at sat phones at one stage there was one or two models that were gsm/sat phones in one. how ever I was talked out of a sat phone by a freind of mines father who spends about 2-3 months a year in remote locations around australia who suggested I just rent one when I need to
A place I'd rather be... Mitchel Road, Bomjinna. Central West Victoria (Jan '08)