migrating ... need help figuring out flights?

hi everyone,

in Sep 2004 our family of 3 will be migrating to Brisbane from USA ...
ideally, we'd like to make our initial stay in AUS longer than 1 year before
returning to US for a brief family visit ...

1) are there any round-trip fairs that allow for a longer-than 1 year stay?

2) are we better off just booking a one-way?

3) should we consider a round-the-world fair or are they all limited to 1
year as well?

finally, Hawaiian Airlines operates a 767-300 from Oahu to Sydney ... does
anyone know what type of seats are used in their business/1st class? how
wide are they, etc.? our son will be almost 2 in Sep. and we're trying to
decide whether to book him a separate seat or just have him share with us?

thank you for all the info.