Yes it is Kalahari Air Services (And Charter).
I spent around 8 years mostly in Botswana doing maintenance not as a pilot. Africa is a great place to visit/live and work, but can have some risk involved.
Botswana is what I would call safe, a fair chance of getting your wallet or phone pinched or stuff taken from your house. But no real violent stuff, more opportunity crime. Very good gun control, basically if your caught with a handgun your straight to jail.
I think you will find being an expat in Africa vastly different to Vietnam (I have only visited a few times). A different mentality.
A quick look today and it seems they are after crew for PC12's but I am not sure if that's a current ad. I also saw Noel's (the owner) daughter is looking after the hire of pilots but Human Resources Officer, Masego Sentle is listed as contact on one of the ads. Masego is a very nice lady and I think you could call her and ask if she has time for a quick chat about possible employment or if it is worth going over for a visit.
I have been back in Australia since 2004, but been back to Botswana 3 times for visiting friends.