speckled sussex outcross would give you sex linked cockerels, but the one good thing, they would all be for SURE single barred roos. And it would get you clear pullets. If you crossed the clear pullets on the sussex again, you'd be free and clear of barring. If you prefer the aloha type, and "need" to cross F1 of the sussex x on each other, you would at least get some clear boys, and some clear girls, and can go forward from there, barring free, if you are VERY strict about not breeding forward ANYTHING that shows the slightest barring. Either way, you are only one, at most two generations from crossing out the barrng gene if you cross to the sussex. Thanks for showing the photos of your project. They look nice. What is your goal size, eggs, leg and eye color? Good luck! Keep us posted.