I guess I should have read your post a little closely - my apologies.
I have done some training and a lot of diving with Ben and JC at the B&J Dive Centre on Tioman. They are friendly and definitely know what they are doing. On the tech side, they teach the stuff they are actually doing themselves which has to be a good thing.
JC in particular is well-known in the cave diving community.
I would highly recommend them and Tioman in general since there are a number of wrecks in the area at 50-80m (Repulse, Prince of Wales, Seven Skies).
I have met Khoo Soo Seng who is the IANTD rep for much of South East Asia, but have never dived or trained with him. Others who have say good things, particularly about his thoroughness and flexibility in scheduling classes.
At the end of this month, I will spend a week at Blue Marlin on Gili Tragawan so should be able to comment on their set-up after that.
... Andy