I think you were going for
beckfordi, from their species name
Nannostomus beckfordi -- or the common name is Beckford's or Golden Pencilfish.
I have a handful of these guys and I love them. Sexing them has been inexact for me, but I think the more red they are (and the more bold the black stripe), the more likely they are to be males. No way to verify that, though -- just my theory.
As far as care, treat them like normal tetras and they'll be pretty happy. But, they also have a lot more personality than most tetras (at least in my opinion).
Their colors do change with their mood, and they do get washed out when the lights are off -- don't let it worry you.
And that was a picture of one of my little guys you linked above
Here are 3 quick videos of my guys acting up back when I first got them over a year ago. I don't know if they're fighting or in courtship (I thought the former, but have been told the latter -- not sure which I believe). Enjoy.
YouTube - Pencilfish Part I YouTube - Pencilfish Part II YouTube - Pencilfish Part III