Take Steve to Men's Wearhouse.
Tell them exactly what he needs. What he needs the suit for. How often he plans to wear it. etc.
They'll do the rest.
You want to go somewhere like that because they'll make sure it fits correctly. And they'll do the alternations.
But Lil' is right. Let them show you the shirts and ties. Then go to Penney's or somewhere similar and buy similar colors and patterns.
Well, I guess he needs a basic business suit to interview in...and possibly work in in the future...will they know what to set him up with?