Out of these, which do you feel would be most rewarding to a knife n00b?

[knifegill]

Petrocephalus Simus:

Pollimyrus Castelnaui

Pollimyrus Nigripinnis:

Brienomyrus Brachyistius:

I find Simus to be the most adorable-looking, but how is the care? Typical live-only regimen?