This is a list of the places I have sourced my materials from and been very happy with. They aren’t the only places to acquire materials and I will add to my list as and when I find others.
Heidi feathers. http://www.heidifeathers.com
Gretel Parker. https://www.etsy.com/uk/shop/Gretelparker
World of wool. https://www.worldofwool.co.uk
Wingham wool works. http://www.winghamwoolwork.co.uk
Fibre Hut. https://www.fibrehut.co.uk/
I haven’t tried Sara’s fibres (postage and taxes are too high here in the uk) but I have hear they are brilliant
Sarafina fibre arts.. http://www.sarafinafiberart.com/category-s/129.htm