Howdy and Welcome!
Thank you for sharing pictures of your birds and for sharing your breed! I love to read up on other
landrace breeds and look at the variations.
As far as choosing which cockerel is best for your flock - what are you looking for? Do you want a bird that's larger in size, with more meat and a presumably better ability to defend itself? Are you only looking at physical characteristics? Are you more interested in the naked neck variation and want to set that as the standard for your flock?
From the way I understand things, choose the birds for your breeding flock based on what you want your breeding flock to be like.
If you want only naked neck birds, discount all the feathered neck ones. The ones you don't want in your breeding flock can be used to lay eggs (if pullets/hens) or make a great chicken dinner.
If you want a large bird, ultimately, choose the larger birds for your breeders. If you want good egg layers, choose roosters from good laying hens.
When you decide on your ultimate goal, choose the birds that most fit that goal.
Because I'm trying to encourage my flock to be "typey", I select hens that are broody, look like feathered bricks, and have good physical attributes. I'm more concerned about their behaviors right now, so their physical characteristics are all over the place, but I'm getting more broodiness out of my pullets and younger hens.
I've had it explained that physical traits are easier to change than behavior. I do plan on selecting for physical characteristics once I get my lines properly behaving like they should, instead of the current trend toward egg laying meat birds for production in a "heirloom" package. It's not really a "breed" unless it has all the characteristics of that breed. A Dorking that isn't broody might look like a Dorking and have the traits, but doesn't follow the purpose of the breed.
An old hand at breed conservation once told me that he keeps maybe a pullet and cockerel from every clutch of 25 eggs he hatches because the rest aren't good enough to keep for breeding, in his opinion. He also breeds and sells chicks, so it's very important that he regularly and harshly prunes his lines to keep to the standard (such as it might be) for whatever breed. Generally, you'll have birds that are more or less what you want them to be, and birds that are more like what you want are better to keep, whether you select for behavior or physical traits.
It's important to keep certain things in mind. If you want a meat bird that's fast growing - select for that. The smaller birds won't be what you want, nor are the slow growers. Choose a characteristic you really want *first* and select for that, then work on the others over time. I was able to find a picture of Pedrês Portuguesa that were marked for a show. The male was a larger bird, beautifully barred and had a black tail and wing tips, large comb and wattles, and was fully feathered. Many of the pictures I found had naked necked birds, so ... personal preference?
Beautiful barred birds, with good size.
Really, In my opinion, the naked necked average cockerel, assuming personality and behaviors are all equal, would be my choice, unless I wanted a Tall Boy or the Meaty Boy.
As far as cockerels having troubles with each other? I've had as many as 13 cockerels together. Once they settled pecking order, it was smooth sailing aside from small scuffles that were mostly for show. That can be a trait you look for and I won't have a human aggressive bird in my flock. Your decisions are your priorities.