The 235/55-17's will fit on the 2004 Bullitt wheel, but because of the offset it will stick out more. I haven't seen this particular combo mounted yet but I would think it would stick out past the fender. Some think it looks good, myself I don't like it when the wheels stick out.
I went with an 18X9 Chrome Bullitt which had a 36mm offset and mounted 255/45-18's which I think came out about perfect. You might want to try searching out somebody with pictures of the earlier Mustang wheels and see for yourself what it looks like.
Here is a picture of my setup FYI