a silver arro can reach 2-3' in length, so without a bigger tank, i would pass on the arro
bichirs can grow quite large too, however alot of them are fairly slow growing and will live for quite a long time, in a 24" wide tank
a tiger shovelnose is another beast, who has the potential to reach 3', or more form what ive read
a royal pleco will be more than happy in there for a long, long time, but even they can grow to be quite large.
you definatly got the monster bug, now can your tanks keep up with it is the question??? the fish you like all have potential to become beasts with proper feeding and tank maintenence
