We have just launched New Guinea lists, based on IOC. The following checklists are available:

New Guinea: the overall island of New Guinea

West Papua: Western New Guinea (formerly Irian Jaya), the Indonesian portion of the island

Papua New Guinea: the Independent State of Papua New Guinea, i.e. the eastern half of New Guinea and offshore islands

These lists are based on those published at Avibase, which do have several errors so please point out any wrong or missing species.