There are several ecn brokers that I have come across and in my experience, I suggest trading with ICM or FP Markets because their spreads are tighter, starting from 0.0 pips with reliable trading conditions.
The minimum opening balance for iCM is $200 AUD and for FP Markets it is $100 AUD, with a commission cost of $3 per lot in FP Markets and $4 per lot in ICM.
From 1:30 to 1:1000 depending on regulation that you choose. For FCA it is usually capped at 1:30. However Iād advice to to choose the smallest leverage possible to limit pernicious temptation to open high-leveraged position which in case of an adverse price movement will cause large loss on your account or will likely trigger stop-loss too frequently.