any corys will go with those fish, you may have to look out for them being picked on like!
most corys grow to about 3 inch. a good sized shoal should make sure they're kept safe
there is a corydoras looking fish called a scleromystax barbatus that grows slightly longer that corydoras though. its a pretty sweet looking fish but i dont know how common it is.
if you are keeping them with discus and angels then you need something that will appreciate the warmer temps, therefore not every cory will go in the tank you have. I would recommend C.sterbai. I wouldnt but S.barbatus in there as they are a cooler water fish and prefer temps around 20*c.
Maybe you could give us an idea of your water temp and tank size and we will then be better able to advise you