Hi and welcome!
If you are going to the US, I'd buy a scope there. The Aussie $ is around par or above and absolute prices in the US are still much cheaper, even with sales tax.
Its up to you whether or not you declare it as an o'seas purchase to customs or not.
Dannat makes a good point about the ETX 125 vs Dob. A 6-8" dob might be
portable, but its not necessarily convenient - quite honestly I find them a PITA. Better an 8" - 10" newt on an sturdy Alt / Az mount. Then you can add digital setting circles later for a "push-to" or use a computerised scope as the pointer.
Both the Meade ETX series and the Celestron Nexstar series are good choices for starter go-to's, though they have quite narrow fields of view.
MY choice would be the Nexstar 6 as, you might want to get an 80-100mm refractor for wider fields, and its easy to swap the 6SE for another scope in this size.
Good luck!
Peter