Your kinda limited to a grid in blocko, so it would be hard to add the 2 or 3 inches of extra legroom business would get.
Warning - while you were typing a new reply has been posted. You may wish to review your post.
Realism would be:
Economy
Economy Plus
First Class
Business Class
That depends on the airline.
It would add more realism if you made three rows of seats. Then again, it all depends on the plan you're going by.
We were going to make a 747ish plane with three rows, but we decided to just on a 737 like plane with 3-3.