Here are some links to companies I have have worked with or think you might find useful:

Coeliac Disease

Coeliac UK
NHS
Codex Alimentarius
Food Reactions
Foods Matter
Grain Information Service
Wheat Free
Coeliac City
Gluten Free on the Go
Coeliac Travel
Gluten Free Passport
Allergy UK

Dyslexia

British Dyslexia Association
Dyslexia Action
Being Dyslexic
Dyslexic
Dyslexia

Groceries Online

Ocado
Sainsbury's
Tesco

Shows

Mary Howard Sales
Macmillan Presents Galore

Other

Firepits UK
National Allotment Gardens Trust
Royal Agricultural College