Buying new corns.

[MartinW]

After reading The Corn Snake Manual and doing some research on the web I must admit I am pretty confused. From what I understand a breeding corn should be at least 3 feet in length. I'd like to breed them next breeding season but I don't know what size I should buy now so that it will likely be the right size next year. Any suggestions? I'm in Ottawa, are there any nearby breeders?

Oh, and I don't mind if they're already adults, although I think I'm more likely to get juveniles.

Thanks,
Martin