I don’t teach IB math myself right now but I’ve seen the syllabus. A disclaimer that I’m only offering advice for Math since that’s the only subject I’ve taken a look at. I will say that the syllabus appears to be (normal O Level track syllabus) + (some basic JC topics). So my advice is that should there be a lack of IB specific tuition, find a tutor who came from the JC track and is competent at H2 Math. I think that should suffice.