I wouldn't base my choice on breed by any means; you can always get a wrong-un out of good parents.
I would watch for the following traits;
Growth; he should be quick to mature, get nice red comb and wattles early. The pullets he fathers will be early layers.
Health & vigour; he should be generally healthy, and while others may seem weak or lethargic at times, he will not.
Curiosity; he should have a healthy curiousity in you when you provide food and water. Please note that this does not include physically touching you; he should keep a respectful distance.
Disposition; he should respect the other birds. When food is brought out, he should be calling everyone to enjoy it with him, rather than fighting over it.
As they grow into maturity, you should then begin to watch for the traits
@HuskerHens18 has suggested. A good cockerel will respect both you and the hens in his charge. Remember to also train this good behaviour; they must learn not to crow or mate hens in your presence, and to keep a respectful distance. If he does follow you, he should be making a happy chuckling noise, never a growl or an alarm call. To train him, advance on him if he does any of these things, and if he doesn't back down, a gentle boot will let him know who's boss.