Finally got my new LED tail light and finished making a bracket for it today. It's from
LED Auto Lamps, fully sealed electronics, ADR approved and cost me AU$30.
Initial tests seem to show that it should do the job nicely

When testing, I found it was flickering a lot when using the front brake, so I pulled out the front switch, gave it a good cleaning and it's working beautifully.
Now I just need to get some more bolts, washers and nylocs, and wire it up properly.