If you're going to play for a club in Sydney, they should be able to give you all the details for accommodation etc etc. If you are working in Australia, you will need a Working Holiday Visa from the Australian Embassy in the UK before you go. They are not so expensive and run for 2 years.
You can then work part time in Sydney to keep yourself in the money. Unemployment in Australia is very low, therefore you should have no issues finding a job.
Flight wise, you'll have to check it yourself. However, I believe Korean Airlines has really cheap flights from LHR
, and their Y service is supposed to be quite alright.
A friend of mine always flies QF
to London and he took Korean because he was really low on cash, and didn't really want to do it. He said the food and service was exceptional and he said he'd do it again in a heartbeat. He was pleasantly surprised.
Sydney is also extremely easy to get around in, transport is extremely cheap compared to the UK, good train system, bus system... food etc and rent is also very cheap. I used to pay $120 per week for one room in a nice 2 bedroom apartment 10 minutes from the city. This is about £50 per week.
You shouldn't have any problems whatsoever. Just remember that it gets really hot in Australia. They just had the warmest Winter on record, with average temperatures in Sydney of 20c. Cricket = summer, so pack no jackets. At all. Trust me. Short sleeved shirts and jeans should get you through.