OneMoreTime is correct and in many states that is the only legal way to title a car that has no clear title to begin with.
If you purchase a title from someone who is selling them (several companies sell original titles now days as novelties) don't try to use it to license your car. If you do you are committing fraud which is a felony in most states.
You can get a title through an out of state title service as has been suggested as well, however several states have caught on to this method of "skirting the law" and will no longer accept them. Ohio is one but I'm not sure about New Jersey.
Your best bet is to follow New Jersey's DMV procedures for titling an assembled vehicle. It may be a bit of a pain as far as paper work is concerned but it's the only legal and fool proof way to do it.