I'm seeking advice on the best approach to transiting the AKL airport. I'm coming in on the UA flight from the US (SFO->AKL). I've got a separate onward ticket on ANZ to the south island a few hours later. If I assume that UA won't check my bags through, I assume I'll need to clear immigration, retrieve my luggage, clear customs, then proceed to domestic check-in. How long would that take on a normal morning?

If UA does check my bags through, can I just go to the transit desk and get my onward boarding passes?

In either case, I'm hoping to perhaps get enough time in the lounge for a quick shower and some breakfast/lunch.