For very low spreads and fund safety I would choose an Australian broker, and depending on my trading volume and the instruments I trade I would choose one of the following.
My personal experience with 5 to 6 figure trading accounts
Global Prime:
Advantages:
Very low negotiated spreads+ commissions. Even lower than if we've used IB's.
They say that they provide their clients with
trade receipts which
show which Liquidity Provider
filled a
trade. 
ASIC Regulated and our funds are kept in Australia, in AAA rated banks 
+ve and -Ve swap charges seem reasonable.
Disadvantages:
Don't have as many currency pairs and indices as other brokers (but its a good selection).
Sometimes not as liquid (My experience) but they are good for most hours of the day.
ICMarkets:
Advantages:
Very low spreads+ commissions when using IB's. I've used HFTGroup (google them)
If you can be your own IB its even better.
ASIC Regulated and our funds are kept in Australia, in AAA rated banks
+ve and -Ve swap charges seem reasonable
Disadvantages:
They only negotiate fees on very very high volume, like 1000 lots per month.
Their live data feed sucks
Their withdrawal system can be confusing and is slower than it should be.
No trade receipts and they refuse to provide one even after compelling arguments (personal experience). A sign that they maintain B books (liquidity is provided by the room next door

)
Pepperstone:
Advantages:
Very low negotiated spreads+ commissions but in order to get those, a trader needs to be trading large volume (over 100 lots per month)
If a trader is not doing high volume then its better to go through an IB (I've used HFTGroup (google them)) but if you can be your own IB it is even better.
Good withdrawal system.
ASIC Regulated and our funds are kept in Australia, in AAA rated banks
Disadvantages:
Their -ve swap charges are higher than they should be and the +ve swap is lower (on most instruments).
No trade receipts (a sign that they maintain B books)
