Regarding Polymer slime powder:
The Polymer (PVA) used for making slime, can be purchased from a number of educational suppliers, e.g., Science Supply Australia, Serrata, OfficeMax, Prof Bunsen, Westlab and from Chem-Supply agents, e.g., Omega Scientific.
It is available either in powder or liquid form as 10% Polyvinyl Alcohol.
The PVA powder can be difficult to use and takes time to dissolve. As a comparison, the PVA solution is quicker and easier to use.
Using PVA acetate glue is also effective.
The National Science & Technology Centre in the ACT has information on preparing Borax slime and cornflour slime. It explains what you need, the method and the science behind the chemical reactions.
Here are the links for Questacon:
Ochre is available from hardware stores (it is used in the building industry) and is available in a range of colours, e.g. red, brown and yellow.
It is also obtainable from Pottery/Ceramic suppliers or any school art suppliers and is available as pigment, inks and in acrylic colour or oil colour.
Art suppliers, such as OfficeMax, have a range of water-based acrylic paints (non-toxic) containing ochre pigments, e.g. burnt sienna, burnt umber, red and yellow ochre. Terracotta and stoneware clay is also available in 10 kg packs.
Ochre can be made using pottery clay from the school art department and adding hematite powder to make it red. The link below has more information relating to ochre.