Known as the Barter Barber, he and Bo will live out of a 1981 Bedford ambulance - towing his state of the art barbershop caravan that Lewis Hamer helped to rebuild.
"This is probably the biggest project I've taken on myself. Where I work we do it all the time, but I need practice," says Mr Hamer.
The caravan will be fitted out with a swing stool, oak mirror and a traditional barber's pole.
He'll also be filming the journey - with the help of a production crew - who hope to produce a documentary for Netflix.
"We'll go back to an area and talk to a person or a group of people that are doing really positive things with men, whether that be down at the meat works or someone's mussel barge, we'll spend the time talking, and talking about talking," says Mr Dowdell.
Sam and Bo leave Mount Maunganui in early February with a goal of visiting every New Zealand town over the next two years.