Metal dishes. They are also good to use in the winter if you use a water bottle because the water in it freezes and its easier to put fresh water in.
Metal feeders. These are nice to have because you can just refill the feeder, but the only problem with these is that they can get moldy if you don't clean them out.
Ceramic crocks. They are great if your rabbit tips its food bowl over.
Water bottles. Make sure you clean these properly and keep fresh water in them, otherwise algae will appear.
Wooden crocks. These are good to have so your rabbit can chew on this crock when you can also still put their food in it.
Make sure when you clean the water bottles or crocks that you make sure there isn't soap or anything left on them that can harm the rabbit if ingested.
You can freeze water or soda bottles and then you can put them in the rabbit's cage for them to lay by and they can cool down that way. The bottles can also be reused.
You could also use a fan to get the air circulating, but don't have it directly towards the rabbit.
Tiles can be put into the cage/hutch for the rabbit to lay on and to use to keep cool.
To keep away pests away from your rabbits or they're cage, keep the cage clean, throw away trash, and if there is any fresh foods in the cage take the uneaten fresh food (such as fruits or vegetables) away after about an hour or so, so it doesn't attract pests.