It's well worth looking at the link with the graphic photos especially since this is something that you want to have done - wouldn't you want to know what the procedure actually entails, including the risks? I read up on it a while back out of curiosity (I wasn't sure what a capon was) and found it informative, especially since there aren't many vets see poultry and probably even fewer would offer caponizing.
If the concern is roosters fighting over hens you could also separate your roosters from the hens and form a rooster flock... supposedly they're less likely to fight if there's no girls to fight over.
If the concern is roosters fighting over hens you could also separate your roosters from the hens and form a rooster flock... supposedly they're less likely to fight if there's no girls to fight over.