For the trampers I'd recommend taking two cars, parking one at the little settlement just past the Mangatoetoe river (think it's called Mangatoetoe as well actually...), then driving back to Te Kopi, parking in the Pinnacles carpark then tramping over to the Washpool, Pararaki, Kawakawa and Mangatoetoe huts and out down the Mangatoetoe. Very nice medium weekend trip. Stay at either Pararaki (closer) or Kawakawa (a bit nicer).
The easy group should ring DoC in the 'raps [to get the phone number] and get permission to cross Pirinoa Station land, 'cos from there its a short pleasant walk up a stream (3hrs according to the sign) to the super nice Tauanui hut.
The beer drinking/surfing group should take their cars and boards around to Ngapotiki hut and sit on the beach, drink a few beers and if there is any surf go and get amongst it.
There you go, I've totally interfered with all your trip planning Tim. But you won't find any angry farmers if you do that....
Richie