Contact the member "Treebird" here. He breeds lilacs and I think I remember him saying he had a few extra young toms. I'm waiting on some of his lilac hatching eggs, so for now I'm living vicariously through you guys in this thread.
https://www.backyardchickens.com/u/177771/treebird
I am actually getting lilacs myself this spring from Porter. Genetically they are not the same as slates.