Nothing else will taste anything like it.
In a salad dressing, I'd only sub soy sauce, as it has the same consistency and brings the umami. Oyster sauce and fish sauce taste entirely different and oyster is thicker and sweeter, making it IMO, not a good sub.
No to the black bean, hoisin and teriyaki, too.
Your salad dressing won't taste like how it's supposed to taste (Thai, presumably ... with lime juice, sugar, etc) but it probably will still taste good.
Edited to add: I just looked at the recipe and it was just as I had assumed. Leaving out the fish sauce will make it taste very different than intended, but there is still enough going on there to be both asian and good. Since there is already soy sauce it the dressing, make it without the fish sauce -- taste it -- and add more soy sauce to taste if you think it needs it.
Personally, I'd go out and buy some fish sauce or see if a neighbor might have some. It's a wonderful thing to have on hand.
Less is not more. More is more and more is fabulous.