Advice on Wairarapa to Porangahau cycling route

Gerrard Smith is wanting to get in touch with someone who knows about routes between Wairarapa to Porangahau. He lives in Wellington and is coming up to Porangahau in January for a few nights holiday with a group of friends. They are planning to ride up (with an overnight stop along the way...) and so Gerrard is trying to scope out appropriate routes and would appreciate any local knowledge about traffic, road conditions, or recommended routes. If you can help Gerrard, please email gerrard.smith@gmail.com