Females trying to lock?

Um. Either one would probably work. If it were bigger, you would have to have a fan to distribute heat evenly. But, i've never used them, so I can't speak from experience. I would probably get the fanned one. Just to be safe. You would think if you ended up with a lot of eggs, and had the bator pretty full, the heat would distribute better with the fan rather than thermal air. But, I can't speak from experience.

Either way, I would plug it in as soon as you get it. Let it run for a week or two to test out temps. And, when you get an ovy, plug it back in right away.