A lot of times you first need to phone vodacom or mtn and give them the imei and pin to add the phone to their blackberry network before the phone will pick it up.
In rare cases you need to get the unlock code from the original service provider where it was purchased and they might have to remove the phone imei from their blackberry network.
Oh the Tour. It was made for American networks but it will work in SA. There should be no problem getting it to work in SA, it uses similar settings to the bold. Obviously you have to register for bis and get the correct service books, but I don't see this as being a problem. Or follow Steveo's advice.