There is a whole bunch of good advice here. North Sulawesi or Philippines (not only Malapascua, but all of the Visayas like Panglao or Apo, south of Negros) are really good choices, both for diving and sightseeing, but regretfully it is a hassle these days getting there from KL. Silk Air still flies on Manado from Singapore.
Of course Sipadan with some tours on Sabah is a great holiday.
Sangalaki and Derawan are very good, but it does take some effort to get there and it is not cheap.
I wouldn't try predicting the weather neither, the seasons are all a bit messed up now.
I also wouldn't give up on Bali right away, still the perfect and easiest destination for combination holidays and the diving is underestimated. Granted, Bunaken and for sure Komodo are better, but the Island has so much to offer in terms of diversity both on land as under water. Diversity that neither Sipidan or North Sulawesi can top, despite the world class diving they do offer.
Of course Sipadan with some tours on Sabah is a great holiday.
Sangalaki and Derawan are very good, but it does take some effort to get there and it is not cheap.
I wouldn't try predicting the weather neither, the seasons are all a bit messed up now.
I also wouldn't give up on Bali right away, still the perfect and easiest destination for combination holidays and the diving is underestimated. Granted, Bunaken and for sure Komodo are better, but the Island has so much to offer in terms of diversity both on land as under water. Diversity that neither Sipidan or North Sulawesi can top, despite the world class diving they do offer.