Some suppliers are shown in the links below:
correx
MDP supplies white correx as used for the varroa screens in a 10 pack 24" x 18".
Click for link
metal roof covers
A roof is relatively easy to make; Bee Hive Bits supply metal roof covers made to measure.
Click for link
varroa floor mesh
A varroa mesh floor can be made quite cheaply. The Mesh Company supply the required mesh.
Click for link
fondant
supplimentary feed in 12.5 kg packs.
Click for link
fish glue
used to glue the small plastic disc when marking the queen.
Click for link