Where exactly are you visiting? Sabah, Sarawak or Kalimantan?
I've been to the first two. 2.5 hours plane ride from Kuala Lumpur to Kota Kinabalu and Kuching. I've heard nasty news about cannibals somewhere deep in the Kalimantan. Pontianak (Kalimantan's cap).
As for jungle, all three would...