I'm fairly sure the US ones have two seperate bulbs, and when you are on high beam bothe the Low and High bulbs are 'on' whereas with the JDM ones only one part of the bulb goes at a time, maybe you need to re-do some wiring.
The JDM lights are not as good as the glass ones you have originally, but you can get brighter bulbs.
The 'style' is not an ordianry H4, It is called either 'H4h' or '702K', (H4h and 702K are both the same thing).
Here is a link to what you can buy:
http://shop.store.yahoo.com/racinglab/raystreetwhi.html
Setanta: You should be able to get them in Australia, I bought some Hella ones a while back for NZ$36 each
NZ and Australia should have the same parts catalogues.
Hella part # 'XG1265/55'
Narva part # '48822'
HTH