I thought I would do a quick search for information about Pakuranga. I used the keywords "iwi Maori and myths Pakuranga" and have only shared links I found on the first page... I came up with the following (books are available from National Library):
- The history of Howick and Pakuranga : Whitford, Bucklands and Eastern beaches and surrounding districts / by Alan La Roche (1991)
- Grey's folly : a history of Howick, Pakuranga, Bucklands-Eastern Beaches, East Tamaki, Whitford, Beachlands and Maraetai / Alan La Roche (2011)
- http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=10348535 (Hidden history of Pakuranga - 2005 news article - talking about a Pakuranga Walk/Hīkoi Pakuranga. Gives iwi/marae/people contacts and keywords for side-searches)
- http://tetahawai.org.nz/ - Te Tahawai Marae is in Edgewater.
- http://www.tetuhi.org.nz/ - Te Tuhi Art Gallery is based in Pakuranga. Although the schools' programme has nothing obvious in there, it could be an avenue. The 'About' page has some information about Ngai Tai and the meaning behind their name.
- http://www.parliament.nz/en-nz/mpp/electorates/data/DBHOH_Lib_EP_Pakuranga_People/pakuranga-people - NZ Parliament Statistics for Pakuranga electorate.
I think the most important thing when researching online is to start general and use the information you get from your first search to refine. From here, I would use keywords like "Ngai Tai and Manawatere" to refine my results.