Hi,
If this can help, my only advice is to NOT buy these:

Zartek COM 8
My father in law bought them from Outdoor Warehouse on our way to Botswana, only to realise that it was difficult to communicate with the car in front of us, and no signal once the distance was more than ±500m. The rechargeable battery ran out so I tried to put in AAA batteries in, only for the handset to go up in smoke
When I spoke about those again at the PMB branch, the guy gave me a smile and said that these are toys for kids.
So yeah, stay far away from these.
The original plan was to use a set of Kirisun
PT260 that came with a roof antenna, but he forgot them at home... They have a wide range on their website:
digital or
analog and they are a good value for money I think.
edit: here are two links to SA websites:
http://www.bi-comm.co.za/Kirisun.html
http://www.radiosource.co.za/products.html