I too am a Sydney Graduate but have been in the UK since 1992. I don't know what the job situation is like for exercise physiologists here. The job situation from a physiotherapy perspective around Bristol is as bad as it is across the whole of the UK. If you want to get work in the sports arena my understanding is that most sports teams want people with a few years' experience (I am not a sports physio- someone else out there may be able to give you more accurate information).
My advice would be not to even try to get work in the UK unless you have amazing skills/ experience that managers will not want to turn away. The new grads have finished Uni in the last week and will be swamping the departments looking for work. I know that physios with experience are not even leaving posts to travel in case they can't get work when they return. I believe that there is no agency/ locum work here either.
Sorry to sound so negative but the easy ride into UK jobs is over and I would hate you to make an expensive move to the UK only to find that you end up working in a bar!
Good luck.