I used to catch migratory hawks for a living, so I have a pretty strong opinion on what DOES attract hawks.
We preferred to use live pigeons with large, prominent, white patches on their wings. This enhances the hawk's ability to see the prey, and thus makes the recognition of, "Hmmm... might be tasty..." quicker and stronger.
Thus, I would strongly recommend avoiding white, or blocky white winged breeds in areas where hawks are common. Something like a Barred Rock or SL Wyandotte is totally fine because that is more of a fine pattern than a blocky patch. Looking at the McMurray catalog, I would say breeds to avoid would be Delawares, Silver Leghorns, similar patchy breeds, or anything all white.
Something like a Partridge Rock or Speckled Sussex would be the safest bird, in my opinion. Nice mottled natural earth tones, big birds. The Production Blacks or Red Sex Links look pretty safe, too.
-MTchick