Owing to how young they still are, you should probably keep both until there is a reason to get rid of one of them. I don't think it would be difficult to get rid of either bird, but it's difficult to say what their behavior will be like once hormones kick in a little more. You may decide that one of them is too aggressive, or that one of them crows constantly, is too rough with the girls, etc. Either one of them would be a good choice to keep.