As an ex-Chicagoan, I am always missing Italian Beefs. Coming from the Northwest side, I miss Luke's or Jay's. Every trip back there, and the first place I hit after leaving O'Hare is Jay's on Irving Park in Schiller Park.
We found a newer place out in Redlands, Anthony's Chicago Style, that is trying to be as authentic as you can out here, and they came pretty close. They serve Scala brand beef, and even import real Gonnella Italian bread to serve it. You have your choice of sweet or hot peppers. The peppers aren't quite right yet....they added onions, and didn't cook the green peppers soft enough, but they are getting there. They will soak the bread in the juice if you prefer it wet. A good size sandwich goes for $4.95, not bad, $5.75 for a beef/sausage combo. They also have meatball sandwiches, made with Scala's marinara sauce. On the side, they offered some decent french fries.
In addition, they have authentic Vienna hot dogs, Chicago style, down to the celery salt. They plan to have pizza soon, as they already have the ovens.
The owner is not from Chicago, but he's taken several research trips back there and seemed to capture some of the best of the local neighborhood beef stands. It's not quite perfect, but quality can very from place to place even in Chicago, but this definitely filled a void for me. It's a bit of a drive out to Redlands, but worth it if you are looking for a pretty good beef sandwich.
They are located at 615 W. State Street and their number is 909/798-1559. Get off the 10 fwy at Orange, turn right, past the movie theaters to W State Street. Turn right, and drive down a bit. It's a little hard to find, as the sign outside advertises their Catering business. They are only open M-S, until 7 pm.