If he buys it in a neighboring state that is one thing, however he will have to store it in a neighboring state as well. He cannot legally own it without a FOID card. I would suggest your wife an FOID and have her buy the gun as she is older if I remember correctly.
Desert Scorpion: I suggest you relax. You are getting all worked up over nothing. Take some of the advice here. You are sounding more paranoid and angry than anything else.
I do not believe that the state can tell you what you can own - period. They can tell you that it is against the law to bring it or have it in that state without thier card but they can not keep you from owning and storing somethin where it is legal to do so. The state does not own you beyond its borders.