yeah sorry i won't keep a 12 inch fish in a tank only 12 inch wide

hello, im new to the forum, but not to fish. anyways, i came here because of well the great knowledge of catfish here. this is a idea i have had for a while now,i have a 55 that i would like to have all catfish. i always wanted a salmontail or redtail catfish, but well i don't have the room(not that ...