have you looked at the hillstream loach/butterfly plec? i was recommended 2 of these for a guppy fry tank they're gentle and shy, the water can't be too warm tho - around 23s best.
I've got 2 hillstream loaches in my 260L tank which is 26C and has an internal and external filter so plenty of oxygen but definitely not a river set up, they have been fine in there.
They were labelled as Borneo Suckers when I bought them.
they've got all sorts of names, sure the guy i spoke to called them chinese butterfly loaches, they were a new import though and still in quarantine so i never ended up getting any, they were amazing little things to watch swimming though.
I dont know if this is good or not but i have heard of having one bristlenose pleco in the 10 gallon tank but i am not sure how big they get becuase i have one common pleco for my 30 gallon. Well good luck.