There’s at least one more brand, but flaked and GNO are not the same as normal oat malt.
https://www.morebeer.com/products/canada-malting-company-superior-oat-malt.html
Flaked isn’t malted at all, so it can’t convert in its own but with base grain it can be. Oat malt just lets you push the percentages of oats way higher. GNO is technically malted but it’s basically a crystal Oat malt so again it can’t self convert. It’s also huskless whereas standard oat malt has a husk(A rather hard one at that), and replaces the need for Rice hulls. A Hugh percentage of flaked will get rather gummy in the mash, not sure about a large percentage of GNO but I’m not sure you’d want to do that for flavor reasons.
I had my LHBS special order them for me the first time I used them but they charged me $4dollars a pound...pretty steep. Since then I just get it online 10 lbs at a time very now and then