Agreed on Rasboras over Tetra in general though as far as non nippy Tetra go, Black Phantoms are a good bet. There is very little nippy behaviour between Phantoms in a social group, males have a very.. hmmn artistic dance instead?I'd probably go with some type of rasbora instead of tetra, as tetras can be a bit nippy. Otherwise decide for one bottomdweller. Kuhlis need rather dense plant and leaf litter thickets, cories rather open sand and some driftwood and plants for cover. You'd be in for a challenge to make it absolutely comfortable for both species at the same time. The bigger the footprint of the tank the better.
I like the limitation in species and the numbers are also reasonable.