Hi,
Guys won't easily give away spots where you can target those species. If you can track down James Lawson-Smith, he might give you some pointers. I dived Sandbaai a few times and sometimes saw some decent fish in the shallows. You need ot be careful as there is a reserve there, and there are reserves in thw town as well.
I had a few spots where you could get both those species, but they are past Gansbaai harbour and so no longer diveable due to the new rules 'cos they can't police the perly poaching.
If you come back towards Kleinmond, Betty's Bay, Hangklip there are some areas you can try find them. Moonlight bay to the right of the lighthouse has them occasionally, there is also a hole that the fishermen target at Dawidskraal that I always wanted to try as they get steenbras there regularly, but never got it right. Just be careful of the fishermen if you do go in there. Maasbaai can produce fish as well, where the slipway is, but be careful of boats.
But to get fish like that in the western Cape you have to put in a lot of time - just cover as much ground as you can.
Cheers,
Tony