My rats are all kept in cages suitable to their stage in life; mums & babies are kept in Alaska Hamster Cages, whilst adult bucks & does are kept in cages minimum 100cm x 50cm with varying heights to account for ages.

Pets At Home XL Hamster Cage, 69cm x 46cm x 41cm (WxDxH)
Used for newborn litters and pairings
Alaska Hamster Cage, 84cm x 49cm x 44cm (WxDxH)
Used for litters with their mum/prior to new homes.
Skyline Barney 100cm x 54cm x 46cm (WxDxH)
It is the same base size as a Coco Large, just shorter – used for older rats.
Coco Large Hamster Cage, 100cm x 54cm x 70cm (WxDxH)
Used for adult groups
Little Zoo Venturer, 93cm x 68cm x 158cm (WxDxH)
Split in 2 for adult groups.

In terms of substrate & feed, all my rats are fed Rat Rations Isamix #7 with Soya and substrate I flip-flop between Bedmax & Snowflake Supreme depending what my local horse shop has available, both work wonders for my rats.

As for toys, I get most of mine directly from Ratatat Toys & Things, with occasional toys from Toogoods Tiny Paws, RatRations (linked above) and some homemade items.

All of my cages are kitted out fully with hammocks, branches, ropes, toys etc that are suitable for the age group.