depending on the size you get your gar at, the knives may be just fine. The only way the kinves would be a threat to the gar is if the gar could fit in there mouths. I wouldnt' worry too much about the knives getting eaten by floridas. Like xander said, that situation which you mentioned was in fact an alli gar and a completely different species.
The catfish should be a theat. I don't know how big some of them get, but I'm guessing the lima and syno don't get too big, so they wouldnt be able to eat gar. Not sure about your other cats though. cats will also eat (or attempt to eat) anything that can fit in their mouths. Other then that, I think you are alright trying this out. Get a nice Florida or two, atleast 7-8" I would say so that they are not at risk of getting eaten.
I don't see a threat of the oscar, but I would see them getting gobbled up, so you may want to rehouse your oscar or setup another tank for him.
The catfish should be a theat. I don't know how big some of them get, but I'm guessing the lima and syno don't get too big, so they wouldnt be able to eat gar. Not sure about your other cats though. cats will also eat (or attempt to eat) anything that can fit in their mouths. Other then that, I think you are alright trying this out. Get a nice Florida or two, atleast 7-8" I would say so that they are not at risk of getting eaten.
I don't see a threat of the oscar, but I would see them getting gobbled up, so you may want to rehouse your oscar or setup another tank for him.
