Well i moved to darwin for a year and changed my licence to a NT one and when i moved back to SA i went to change my licence back to an SA one and they were gonna keep me on the NT system because they thought i originally got my licence there, but i explained it to em and got back 2 the SA system...
So i dunno how u would go changing your licence over but i mean hey it would b worth a try, i mean all u can get is a no.
One thing worth a mention tho is i love the NT system how u don't loose points for speeding no matter what state your in.... One of my mates managed to get one and he lives in SA got done doing 160 in a 110 zone which is instant loss of licence but the cop saw his licence and just said yep no worries