In the 60631 Zip - Good place for Business Dinner
There are some nice restaurants in that area, but nothing that screams great and "expense account" in the area.
That being said, ZIa's Trattoria is a nice place (Italian) and they can certainly accommodate a party of 8. http://www.ziaschicago.com/
For steak/seafood, Elliott's Seafood Grille and Chophouse is pretty good (especially for steaks), except that it's a little small. http://chicago.metromix.com/restaurants/seafood/elliotts-seafood-grille-and-edison-park/138197/content
A little farther away is the Black Ram, which is a very nice, old school restaurant specializing in continental food/steaks, all of which is very good. This may be your best bet in the area and it's not that far from 60631 -- it's about 10 minutes northeast (mostly north) of O'Hare. http://www.blackramsteakhouse.com/
If you are trying to be close to a particular spot within that zip code or you're willing to travel a bit, please say so.