You've got to be really quite careful and take some time easing off that black shroud for the cluster, as its very easy to break the tabs that hold it on. It took me more than ten minutes of small movements side to side, in and out, to get it off without breaking. If you just reef it hard it will more than likely break those tabs, so take your time and use a lot of small movements and not too much pressure.
The direction of movement to release the shroud is directly towards you (sitting in the driver seat) and not up and away from the dash.
This may help with bulb choice (listed in top left corner of the cluster photo) but I'm not sure if they are called the same thing in Australia.
I have tried LED's in one of the clusters I have, and the LEDs with the flat top are kind of narrow leading to uneven illumination, I actually prefer the orignal lights than LED's.
Another reason to go with the filament bulbs is that they are a more even match in brightness for the other bulbs in the interior. The LED's in one of my clusters being so bright I dimmed the dash further, but then the lights in the heater panel are dimmed to almost off and its a bit hard to see it! Sorry I'm probably rambling now...
In that m.net thread look further down the page to Lokiel's post about the LED's he bought, there's a photo there of a NeoGaugeLeds package with some star looking ones which I think would work better for an even illumination.