I am currently trying to break into the PVC-U door panel production area of the market but I am having trouble finding suppliers for the skins needed to produce this product. Could you help me with finding a supplier?

Glass applications is a specialised subject and is controlled by a number of British Standards so there is no one answer to every application. I recommend that you consult a glass company in your area that concentrates on windows and doors and explain the application you have in mind. I have no doubt that they will offer advice concerning your specific application and may also provide you with double glazed units that most importantly comply to the relevant British Standard.