I think most people underestimate the predatory abilities and size of chocolates. I think most of the tetras that you will find available in LFS will end up as snacks. Best bet would be silver dollars, unless your tank is planted.
I have never kept discus tetras and can't recall if I have ever seen them for sale. I came across them on a great world-wide search for a smaller alternative to silver dollars as dithers for oscars. From what I understand, they max out around 3.5 inches and have nice deep round bodies. They are kinda like a mini SD.
mini silver dollars is exactly what I thought when i saw them.
my blackskirts are larger than any columbian tetras i have seen so i think that would end the same. good suggestion though.
my tank is not necissarily planted, but i do have plants. i keep a large amount of floating anubias. my chocolate does mess with them, but they are thriving. he loves the cover so thats the only reason i have not dont sd's yet. you think the anubias would stand a chance?