Best brittle star?

[Littorina]

Hi everyone,

     I'm looking to get a brittle star to eat leftover food (flake, mysis, etc) in my system.  I have 3 nassarius snails in my sandbed, but they need help (plus I just love brittles and have always wanted one).   I want one that's not going to be aggressive to my other inhabitants, and not too big once full grown (I have a 28 gallon with a 1" sandbed)....

There are the usual black/tan banded ones that many get as hitchhikers, which would work, but was looking for other suggestions as well.    I'd LIKE to have a species that comes out a bit during lights on, but I know that's rare.

Advice?  Experiences?
Thanks.