Try the following sites as a good source of manufacturers:
What you can do is contact them, discuss with them you want some SAMPLES firstly to trial out the product. All manufacturers should allow for samples, they will charge you alittle more for it, but it will give you a chance to get those screens. It might be alittle more difficult to find a manufacturer of the screens though.
One point of advice, always HAGGLE the price down as they will rip you off! One trick I've found that works is say that you have another supplier that can supply it to you CHEAPER. I've found some will reduce the price because of this.
Hope that helps.