After all the talk here is the rifle I ended up ordering.
A Searcy 500 nitro express double,of coarse.
I also opted for scope mounts but have yet to install them.
Thanks to the advice from members-and a lovely piece of kit it is too.
The paperwork between Australia and the USA is terrible but can be done-if this is what you want don't let the bureaucrats beat you.
By the way, the rifle is resting on an impala skin.