may i ask why the interest in blue cats? they get massive and are not suitable for tank life except at bass pro shops. if you realllllllllly want to keep one, get a VERY large pond and it can have no pondmates.
if you have a chance to get a blue cat get him they are awsome crazy for food. flatheads are just cool they dont do much in a tank. i get my baby cats on accident because i catfish for big blues and flatheads in the ohio river so i get them accident when i throw a cast net to get my shad
Both get too large for (Normal) Home aquariums, but either can be kept for awhile, but will need larger housing at some point, or get the slaw and hush-puppies ready