My bourbon red turkeys are just starting to get mature at age 7-8 months. My hens started laying eggs at 9-10 months. the BR toms will get to 15 pounds (dressed weight) and the hens will get to 8 pounds (dressed).
I don't know about the other breeds. My 1.5 year old RB tom is significantly heavier than the 7 month-olds.
hope that helps.