can anyone help?

i am emigrating to australia in february as a permanent resident and have savings in a high interest savings account and a cash mini isa here in the uk. with the exchange rate being so poor at the moment is it ok for me to leave them in there for as long as i want before transferring them to oz through currencies direct or hifx? will i be taxed a lot or not? anyone got ant recommendations when to transfer/which company to use??

any advice would be greatly appreciated thanks