if you are going to be buying off trademe then stick to brands you have heard of.. i would easily suggest going to PI rather than buying off trademe as there is absolute crap on there thanks to the useless importers who take advantage of those without some common sense to do the research first.
Be aware of apine (alpine knockoff), explore (sony xplod knockoff) etc etc on trademe.. regardless of cost you come up with issues such as not meeting specifications, poor quality goods, inability to return goods for warrenty or purchase etc
In all saying this.. PI is no better in providing valuable service advice either (forget about the warrenty sometimes.. they can be a right PITA to deal with..

they may have the equipment but i know that various amounts of it is either b-stock or repaired and dumped in NZ..
seriously - go here:
http://forums.nzicemag.co.nz and make sure you spend your money right with some advice from people who actually know what they are talking about..
and my 2 cents.. for 6x9s.. Pioneer/JBL/Alpine..
for 4" coaxials i'd be telling him to get some 6" coaxials to ensure that you get some sound up front.. go check out
http://www.jaycar.co.nz - their old 4" coaxials were very highly regarded a couple of years back
