Why do you want 3mm spacers? You won't even be able to tell the difference so it's pretty much just a waste of money, unless you need exactly 3mm to clear brakes or something.
-edit-
Nevermind, just saw your second post, sorry.
You could ask if it would be possible to just buy the 3mm ones separately.
http://www.projectnissan.com/shoppin...idproduct=2580