The chances of finding JDM projectors is slim and they're expensive, so RHD specific retrofit parts are the next best option. Having said that, I wouldn't have purchased USDM lights in the first place as we've already stated they are not suitable.
In the case of claiming in an accident, the Insurance company will try to get out of a claim any legal way they can. You're car will be thoroughly investigated for any unspecified modifications & customising to use as an excuse not to pay out.
Here Awais, do some homework on how to retrofit the projectors. You might go that step further and look at a Quad setup. You don't need to be a rocket scientist to separate fact from fiction
http://g35driver.com/forums/lighting-177/ - lighting secion
http://www.hidplanet.com/forums/ - HID forums
http://store.theretrofitsource.com/product_info.php?cPath=25&products_id=153&osCsid=e4f32fb9dec0508940f6a2d5685f3015 - parts supplier
http://www.auto-electronic.net/INFINITI-FX35-Bi-xenon-Projectors.htm - another parts supplier
Blanket statement which is not entirely correct, any modification to your headlights not meeting ADR or NCOP can still result in a defect notice.
http://www.infrastructure.gov.au/roads/vehicle_regulation/bulletin/vsb_ncop.aspx
Genuine Nissan USA still doesn't make them original AU fitment when you're talking LHD v's RHD headlights. Yes you can adjust the projectors left/right & up/down to a minimal degree, but how do you "twist" the projector so the beam cutoff is angled the correct way?. If it was so do-able as you say then all LHD & RHD cars models would share the same projector unit.