Just throwing it out there, the only difference between the 10A and the 15A 240v plug is the Ground terminal size and its only bigger to prevent it from being plugged into a 10A socket. There is no electrical reason for the larger terminal.
Now for the wiring in the house and the circuit breaker, what you need to do is check the size of the copper cable thats running to the GPO you want to use for your compressor and how far away it is from the switch board. You can then go to a site like this,
http://www.calculator.net/voltage-drop- ... 0&x=22&y=4
and work out your voltage drop. Alternatively you can just plug the compressor into said GPO and measure the voltage at the compressor while its running and compare it to the voltage at the switch board. Too much voltage drop means the copper is gonna get hot and you risk burning your house down (the compressor will also under perform). I think the recommended max is around 10%. Remember to take into account other things that may be sharing that copper (for instance, its common for GPO's to be hopped from one to the other, all with a single conductor back to the switch board).
Please be careful if you do probe around in your house's wiring. Rubber gloves might seem goofy and for whimps but I use them at work all the time when doing tests on High voltage, especially when its not isolated. Double check with a meter before touching stuff.
Few other things to note, brown is usually active and Blue is neutral. Its easy to remember because if you touch the brown wire, your gonna get brown undies. I still dont recommend touching the blue wire though. Some sparkies have painted on brains

and especially in my line of work they get it backwards all the time. If its 3ph then the neutral will most likely be black.
Man I can ramble on. Long story short if your voltage is dropping more then 20volts at the compressor I would probably get the copper upgraded.
Regards
Doug