i totally understand about the 'fragile fish' thing. they are not the most fragile species and the pair of peppered corys i had once were some of the hardiest fish i've ever had, but maybe that's just because they managed to survive several cycling tanks, several bouts of finrot and my appalling early fishkeeping skills
they are very sensitive to medications especially salt. and they get stressed easily. but like i said my peppered corys were always fine and lives for years. maybe the terrible conditions they went through in early life toughened them up.
i think some species are more delicate than others. for instance i think sterbai are meant to be able to tolerate higher temperatures, while many other species have shorter lifespans in temps above 25 degrees celsius. i'm not too clear on any of that , its just the impression i've got from reading stuff.
corys were my first ever tropical fish and although i had a few deaths to start with, when my tank finally cycled ( i knew very little about cycling back then) i kept a pair for about a year with great success. i'd reccomend them, but i think a stable tank is a good idea, and you want to make sure the corys are as healthy as can be and that all the other fish in the tank are healthy, and there's no stress, because they are a pain to treat if they get sick.
i hope you get some though,they are a delight and i've never found them hard to look after :)