Food may be an issue. As the bgk uses electrical impulses to find live food. Bichirs use smell and when near sight. The bichirs may out compete a bgk....I don't know for sure but have been looking into them as I have always liked bgks. I have a very good lfs and have talked to a few people there on this subject they have one it a very large tank I think 280 not sure. It's 16" and it's been in their care for its entire life. It will eat pellets but it took years for that to happen they said. I don't know for sure but from some of the things I've read seems posible.
Wow it took years to accept pellets? Mine accepted pellets really early on. They do go crazy for bloodworms though. I did feed him bloodworm's before he had tank mates. But since tank mates at around 6 inches or so he happily accepts floating and sinking pellets.