I have a lot of roosters that are savvy to the hawks and call the alarm and they all run for cover. I've lost one or two that didn't listen. Everyone is free range daily while I'm repairing two coops.
If not in the US at least the thread posted has some info on where to start. I know Silver Laced Polish is in that mix and Silver spangled Spitzhauben were used here to bolster the survivability of them at a hatchery. I would go with silver based moorhead colored birds. Moorhead is the black...
I would start with a few birds from people already working on the project. There is a thread here from someone that is working on the project. If no one is where you are Ill see what I can find on this forum to help.
Ill get a few posted and snap a few more as I have some new sebright corsses. They will be phoenix x sebright x spitzhauben mixes. Some have Ameraucana in them.
Silver Sebrights are silver based as are Silver laced Polish. There is no dominate white in them. If you were going buff laced, then you would want to have dominate white.