First you need standing to sue. That means a wrong has to directly be committed against you. An arrest for having a gun is the most obvious, and I do not recommend that approach at all.
What are the FOID cards in Illinois and how does that system work? If you can get ahold of Bob Levy at the Cato Institute, that's the guy to talk to about this if you are serious about challenging, or know someone who is serious. The right test case can make the difference between winning or losing. If Heller was a stereotypical "gun nut", he'd lose.
Gura, the lawyer behind this case, has ALREADY filed a suit in Chicago. It is BIG, the whole enchilada, INCORPORATION and all.
http://bfa.cros.net/OrlovChicagoComplaint.pdf
http://www.chicagoguncase.com/