I just wanted to post this to recommend the private guide we hired during our Borneo trip last year - Hadi. We booked via Wildlife Expeditions in Sandakan, who contacted him directly on our behalf when none of their standard itineraries exactly fit what we wanted to do. He can also be contacted by email: Hadiabdullah7@hotmail.com.
I can't recommend Hadi highly enough, he really went out of his way to give us the best experience possible. For instance, when we visited Sepilok, as well as seeing the feeding, we also went trekking further into the park, which we noticed most other guides didn't offer. This meant we had additional sightings of orangutans in a more wild environment, that we would otherwise have missed. Similarly, at the Gomangtong Caves, we went past the Black Cave into the lesser-visited White Cave - Hadi said we were his first tourists all year who'd wanted to go, which felt kind of cool! He didn't push us, but made sure we saw and did everything we'd hoped for (as far as possible - obviously he can't guarantee the animals sightings!)
We also spent a couple of days & nights on the Kinabatangan River, and Hadi was tireless in the heat, helping us to spot proboscis monkeys, macaques, hornbills, snakes, crocodiles, and my personal highlight - a pgymy elephant.
As well as organising all the logistics of our tour (transport, accommodation, meals), Hadi lastly also arranged our onward bus tickets to Semporna and even waited with us at the side of the road to ensure we got on safely.
I hope that some of you might use his services in the future as we found him absolutely terrific.