The problem is: Nintendo uses ANYTHING they can get on market to assembly their Joy-Cons so almost any parts can be considered OEM, and there is no a list of OEM providers to Nintendo.
I do recommend to buy the kits with Sticks and other parts, and buy the ones with 4 sticks, I am using now the ones I buy for 20$ (4 stick, 2 metal lock, set o new screws and set of tools) and has been almost 1 year without problems nor drift. I did buy that package for my wife and my consoles, and the 4 of them are working like a Charm.
Do no try to buy "expensive ones" just because they could be OEM, think about: the original of Nintendo drift soon. so others cheaper could or no could drift but you didn't spend lot of money.
Do not forget to put some paper or thermal pad at the base of the sticks, that will avoid the drift for some time:
look at:
