I looked this one up and it is more suited for large area work such as single color tank and ship schemes. It would work if that is all you do, but I saw a few more brushes on the Tamiya site that would do more detail in the eveny you did say.. 1/72 or 1/48 aircraft. The one you listed qoutes at being able to do detail lines at 2mm, the two below are rated at 1mm and < .5mm (for the top link I believe.)
The Tamiya HG here would let you do fine detail such as freehand camo (with practice) and spray large areas as well: http://www.tamiyausa.com/product/item.php?product-id=74503
here is another:
http://www.tamiyausa.com/product/item.php?product-id=74519
Another brush to think about in your area would be the Iwata, they are made in Japan (those Tamiya brushes look suspiciously like Iwata knockoffs, in fact that wrench you see in one of the links I provided on the Tamiyas, is the same Iwata nozzle wrench I use on my Iwata HP-CR)
Here is the Iwata HP-CR, I was able to do 1/72 Luftwaffe camo freehand with it:
http://www.acehobby.co.nz/OSSB2/Root/ossbec3/ShowItem.asp?PID=49391
here's a more durable and longer life (and quieter) compressor to go with it:
http://www.acehobby.co.nz/OSSB2/Root/ossbec3/ShowItem.asp?PID=52169
If noise is not an issue a regular hardware store compressor works fine too. My modeling room is at the very back of my house and my wife doesn't even hear it when she is in the front watching TV so it works out fine. Here they run about $70 US for a smaller one with a tank, compared to the $159.00 US or so for a hobby one without a tank like I listed for you... (the tank helps by dampening any pulsation int he line and making the compressor kick on less often)
Good luck! I will see if any of my Aussie buddies on here have suggestions since you are relatively close geographically. Many of them order from www.dixieart.com here in the US and say it ends up being cheaper than buying them in AU due to the low price of the equipment itself. It might be the same for you. the compressor I listed from the hobby shop in NZ for $299.95 NZ runs about $149.00 US at Dixie Art, converted the NZ shop compresser would cost $220.00 US. I am not sure if you have a high customs rate or VAT but it might be worth checking out.