The best hay is timothy hay, brand doesn't matter whatever your chin will eat, if you are getting it from somewhere that does different cuts then go with 2nd cut. The hay feeder there isn't really one best one, it depends on what works for you and your chin. Personally I have wooden boxed that hang on the side of the cage (the holes use to be chinchilla shaped)
You can get similar ones one etsy as well as Nola Chinchilla Rescue sells ones similar.
Some people also find wide a bowl works for hay, or a clay pot. Some people make fleece hay sacks (hay will stick to it so they can be hard to clean).
A few options that you can find in pets stores that are safe though are these
the wood manger one a lot of chins chew through quickly though, the ware hay rack goes on the outside of the cage, and the All Living things one needs to be the ceramic one not the plastic. The metal bars need to be removed since chins have jumped on the feeder and gotten a leg caught and broken.