Advice on Visa

Hi

Looking at moving to UK with my 4 kids April/May 2017 if possible as we need to follow the process of relocating our cats.
Have been doing research but would just like to confirm that my thinking is correct.
We are looking at selling up and making the jump so cannot afford to get it wrong.

Not sure if we get the visitor visa as this allows for 6 months only and you need to have sufficient funds which we will not have after all expenses are paid to make the trip possible and it doesn't allow you to work. If we do this and then find jobs and get settled, not sure if we are able to change to a work visa while in UK or if we need to go back to SA.
With this visa it does specify that you will be going back to SA but that would mean a return ticket which is a waste of money if you plan to find work and stay.

So the way I see it is to get the 2 Tier work visa which means we should all secure jobs and get sponsorship for the first month.
My brother is a UK citizen and his kids have their own businesses but not sure if this would qualify as sponsorship if they do not appear on the Register of Sponsors Licenced list.
Also have a good friend who can offer me a job and assist with housing etc to help us get on our feet but then need to ensure my kids are secure too.

Would really appreciate any and all advice on this and if there is a step by step guide to help us make the entire process easier so that we do not miss anything as it is a huge change we are going to make and there will be no going back.

Look forward to hearing from those with experience who have successfully made the move from SA to the UK.

Much appreciated.
Regards
Audra