TTE normally done by Sonographer in Cardiology Dep. the report will be reviewed by Cardiologist. Some ICU doctors can do TTE as well.
Abdo Echo done by Sonographer, but ED doctors can do it.
TOE normally done by anaesthetist, cardiologist should be able to do it.
ECG done by nurses, result will be reviewed by doctors.
ECG's are everywhere in hospital, ED, ICU, Theatre, Wards, Outpatient...
Also AED Defibrillator are available everywhere in hospitals.
You have to pass OET, at least B or above in all four subtests if you can not pass the IELTs test.
If you are in Victoria, you need to contact Nurses Board of Victoria,
look for Pre-Registration and Initial Registration Courses for Overseas Qualified Nurses
Not sure what do you want to know, if you want to be a doctor, sonographer not suits you.
Abdominal ultrasound all done by sonographers inside hospitals or in some diagnostic clinic.
Just gooooogle it. Most of them located in Major cities,
Melbourne - Royal Melbourne Uni, Monash Uni
Sydney - Uni of Sydney, Uni of Western Sydney
...
Follow the link below: http://www.australian-universities.com/schools/medical/