What are your goals for those cockerels? Why do you want to keep one? My personal preferences and criteria aren't what is important. yours are. What criteria are you looking at?
If you are looking for behaviors they look too young to put a lot of faith in that. Their behaviors can change as they mature and having more males around can influence their behaviors. They may have disqualifying behaviors now but may seem OK for now but can change later. It's not always easy.
If you plan on breeding them, what do you want the offspring to be like? Since they are crosses and I don't know what you would be breeding them to it's hard to talk about colors and patterns. The red one would more likely allow the hen's colors and patterns to shine through. The black one will probably give you a lot of black chicks.
The naked-neck gene is dominant. If just one gene shows up the chicken should be naked necked. I don't know if their mothers were naked necked or if they had the same father. The black one should give you some NN chicks, the red one will not unless they get it from the mother.
The longer you keep them the better choice you can probably make, but basically it comes down to which one you like the best.