You appear to have done various bits of training all over the place!
How recently did you do the 30 hours in Malaysia? I'm not sure if any of the schools here would be prepared/able to credit you those hours towards a PPL(H), but I'd definately ask around - even if you get half of them credited, that's 15 hours towards your PPL!
If you did a South African PPL, I believe you'd still need to do the skill tests (ie. both R22 and R44) here to get it converted. Check LASORS for that.
As regards training here, while Heli-Air are very good, be warned they aren't the cheapest. Just a thought. In addition, you might find that some of the other operators in SA are a bit cheaper than Base4. Also, accomodation and living costs will be lower outside Cape Town (although if you're paying in GBP, it's all pretty cheap).
As regards the UK PPL theory exams, I believe you have 18 months from passing the last paper to pass your skills test, not 24 - again, I'm open to correction here, so check LASORS.
Basically, as has been said before, you need to decide what you want to do. If you're only planning on flying for pleasure, then it doesn't really matter where you train, so long as the quality of the training is decent. If you want to ultimately work in (say) the UK, the more of your training you can do here, the better. Just make sure you've considered all angles before you commit
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