I just saw a LARGE suncat on the weekend..it was almost 7"....thick. Crazy. Keith listed a lotta species that would def. work....I'd look into them if i were you..
good info for anyone esle thats interested. not many shops get various cats here so thats the other reason i went with the sun cat.
what about Synodontis eupterus? 1 shop got those fellas in. My bro got some in his 120.
since you have though, I can say that all you need is hiding spots and anything will do. My rhino in the 150 is most likely female but the one i put in my 55 is way bigger and most likely male, so might try mating... The sun cat is now with a red tapajos and is about 6" now.