These are some reccomendations for rat supplies. Hopefully this will make your search for supplies easier, whether you buy these products or they give you ideas.
*This is not an advertisement for any of these products, it is simply a list of some products I found that are good for rats.
Click on underlined words for links!
Cages
MidWest Homes Critter Nation Cage - 864 inches of floorspace & 39 inches tall
PawHut 5-Tier Cage - 645.75 inches of floorspace & 50.5 inches tall; for larger rats since the bar gap is almost 1 inch
PawHut 4-Tier Cage - 420.25 inches of floorspace & 44.75 inches tall
HABUTWAY 4-Tier Cage - 420.25 inches of floorspace & 44.7 inches tall; for larger rats since the bar gap is almost 1 inch
All of these cages will need to be modified for more bedding space. See how to in this video.
Wheels
Kaytee Silent Spinner 12" Wheel
Hides
LEFTSTARER Fabric Hammock Hide
TRIXIE Suspension Bridge & Hammock
Food & Water Containers
Living World Glass Water Bottle
BUCATSTATE Water Bottle With Ceramic Holder
Sand Baths
Zoo Med Reptile Sand (though this is made for reptiles, it is safer for rats than most sands)
Chews
Bamboo, Apple Brance, & Timothy Grass Chew Sticks
Bedding
Hay
Food
Kaytee Fiesta Mouse & Rat Food
Sprays