Hi I emigrated to Jo'burg 5 years ago and have been pretty happy here ever since. we have a high standard of living, nice house, pool, can afford help around the home. the weather is fantastic and therefore it is a very outdoors culture, we are in the pool, at the park most weekends, going out for breakfast is quite a big thing here ( it gets a bit hot later on in the day) and there are some lovely places to go with great play parks for the kids.
We go down to Durban every year for a week or so and I love it, if I could live anywhere in SA it would be there, Umlanga and Balito on the North Coast are the nicest IMO, beautiful beaches, very laid back lifestyle, like a nice surfer type community.
My salary here is probably a bit below what I could earn in UK but we are much better off as child care is very cheap. I have a full time nanny for about 400 pounds, also a cleaner and gardener 1 day a week so I actually get to spend time off with my kids rather than domestic stuff.
with regards to a package for DH, he needs a comparable wage to the UK as well as decent relocation allowance. check website for rental prices along the North Coast, to buy you will need at least 2 million, prefably 3. Renting can be expensive and most rentals are completely unfurnished. some things are a lot more expensive here - cars -you will both need one and will need to allow at least 100 000 zar for something vaguely decent.
Check discovery.co.za for prices of medical aid, it's expensive but far better quality than in UK. You also get very cheap gym, cinema and other benefits (25% off BA flights home) with vitality from Discovery.
white goods are very expensive to buy so try and get a furnished rental. there are no free schools here, you get what you pay for, allow 30 - 60 0000 a year depending on the age of your kids so make sure you allow for that.
Crime yes it is bad and can be violent, I've never had a problem but know plenty of people who have, armed robberies and car jacking are not uncommon. I don't have a gun and don't know anyone who does, asking for trouble IMO. I get the sense that Durban is much safer but I have only ever visited on holiday, I would always live in a gated community here, but none of my other friends do and they seem quite happy.
Schools are very good quality and very multi cultural so your kids should fit in just fine, they will also get exposure to lots of different languages and cultures which I think is a good thing
with regards to inequality, yes it is massive and can make you feel uncomfortable. however my view if that I employ 3 people who wouldn't have jobs otherwise, I pay a decent salary, give them all my old clothes and stuff which if they don't want they can sell, lend money if they need etc. Also if you are not working then you can potentially get involved in volunteer work and really make a difference, there are tons of humanitarian organisations who would love to use your time. so if you have the right mindset then you can actually make a meaningful difference.
I would definitely come, you'll have a great time, learn lots, start to look things differently your kids will enjoy a great outdoors lifestyle. But come with your eyes open, live someone sensible, be careful etc etc
please PM if you have any more questions, I can point you in the direction of more websites if you are looking for any specific info.