Sort of depends on what you want as an end result.
so
I reckon go for he 1/4lb. That way they can grow into their environment, or, if something goes wrong, you minimise your loss.

If it were me, I'd find a 2 cu ft bin and use the 1/4. More room for error.

Cheers

jake 1: how are your ANCs doing? I've gathered some info online, but am always interested in hearing "real-world" experiences.

Thanks,
Andrew