Silkies are good broodies but silky cross are best, as silkies feathers can mat up and chicks get caught in them. If you use a sussex the chicks on the first cross are coloured dependant on sex, cocks white hens buff so if you want you can only keep the hens. Welsummers will be as good as any or if you can get some, Hamburghs as these are hardy and good forages.
thanks for your help mate..