Avoid the common boxer Stenopus hispidus.
Stenopus scutellatus, Stenopus tenuirostris, Stenopus devaneyi make better choices as I have kept these before and they don't exhibit much aggression to small fish except to their own kind. My S.devaneyi was actually about 2-3 times the size of my S.tenuirostris but it got bullied by the small fella as it was in the tank first.
A link I found..not in English
See so peaceful..