They are left hand parts, you can only install them with your left hand.
There will be some differences no doubt but you probably have to take it on a part by part basis. I know from reading some of the US forums there is many items that have slight differences according to the way people describe them and the images they post but I'm not sure you'll find a definitive fit or not fit guide to US parts.
A mate of mine has done a lot of ordering of parts from the US for other vehicles and he's had no real problems with part fitment but he's also done his research so he knew what he was getting and knew that it would fit before purchase.
Download the Frontier manual and although it wont give you all the parts it might give you some information as to the parts you are after and whether or not they show anything like what you can see is needed for your Nav.