Check the buy/sell/trade section for PHR-803T sleds. There are quite a few members sourcing and offering these for sale lately. Depending on the seller, you can grab them up for around $20US average.. Some sellers even offer to harvest them from the sleds for a small fee. Figure in a bit extra for shipping to AUS...
The only way to get an exact 120mW, or even know for sure that you have at least that power, is to check with a meter. These diodes vary quite a bit in output. One could output 120mW by being fed anywhere from 125mA to 160mA of current. A heatsink is also absolutely necessary if you expect these to last at these currents.
Send Spyrorocks a PM, he has some PHR-803T slede for sale at the moment. [smiley=thumbsup.gif]
EDIT: You'll have to write more posts before you can send a PM.. not sure of the number..
You could also run a B0323 diode at 120mA. Just a warning, a 120mW PHR won't last as long as it could at a lower current... These diodes were made to put out 60mW. I would run it at 100-110mA, which would give you 75-105mW. Or like I said, the B0323, though those haven't been tested much.