I can attest that hoplo catfish are active, mine will be up at the top checking out what everyone's doing while silently plotting to steal their food when they aren't looking.
99% of Lima shovelnose sold are actually elongatus and only get to a foot so a school of them should workLima Shovelnose school but would eventually need more space though it takes them a while to push past 14", max size is around 2ft depending on the species but only a handful have been seen at that size
I've got a 170g tank being custom built for me. 60x30x22. Which actually has a larger foot print
(in square inches) than your run of the mill 240g tank.
I have always wanted to have larger cats but space was always an issue before. Can you guys recommend a species that wouldn't get enormous but would look awesome in a group of four or five? Four line pims? pictus perhaps? I'd like them to be an active species. Other tank makes will likely be SA or CA cichlids, plecos, possibly a Fire eel as well.
Wet spot has Ornatus for $35ea.
Sounds like your looking for some sort of Pim
As suggested above if you could get Pimelodus Ornatus these are stunning and like to be kept in groups , thou they are rare and pricey. I only have the one and trying to find more in the UK is tough may be easier in the states to get some.
And also suggested above Pimelodus Blochii ,four line pims which are the most active Catfish outside of Hoplo's i have kept ,again i have only kept the one thou they are quite easy to come by.
Wildwoods Enfield has had one a while, not sure if it's sold. They do mail order.