I've got a copy of the Oxford guide to the birds of the Philippines you can borrow. I've been to Palawan and it seemed to serve me pretty well. I missed the Palawan Hornbill however by about 5 minutes.
I live in Causeway Bay right near the Excelsior hotel. I'm usually home by 7:30 PM if you want to come by I can meet you there and hand it off to you. Here's my cell phone: XXXXXXXX.
Palawan is stunningly beautiful. I'm sure you'll enjoy.
- Josh