I have kept bumblebees and know them well. I think you are right, I should just stick with wild color forms
Only thing I would worry about is the longterm effects of the high temps on the tetras and knifefish. The tetras are easily replaceable money wise but I don't know about the knifefish never bought one. But that being said the bumblebees should be kept in even lower temps and I had one for 5 years in with discus. One thing I would watch for though with this type of group. Don't get small tetras or they will be expensive feeders between the catfish and knifefish.could I add a steatogenys duidae or two instead of gouramis. So here is updated plan
6x discus
2x abn
4x bumblebee cats
10x diamond tetras
2x steatogenys duidae
knifefish are generally found in warm waters and should be fine I think. but will they be discus safe?