United Kingdom looking for leather wear items

Hello,
I am looking for a clothing manufacturer that I can build a long standing relationship with to produce clothing for a new and exciting fashion brand.
Initially I will be looking for around 20 styles, 100 pcs each in a range of t-shirts, trousers, shorts, dresses, skirts etc.
Style is minimalistic and all black and white, mostly made in leather, cotton and polyester.
This is an initial request and I will be looking to expand quite quickly providing the initial venture is successful.