I'd go 18s, they are pretty much the "norm" now. Big is considered 19 or 20, but those are too big, IMO. Plus, tire choices in 19 is limited and the 19/20 is a bit more expensive. 18x9 on all four corners or 18x9/10 staggered is the ticket ;)
EDIT: you can get a deep dish Bullit, too I think...