Reece,
Check Dawson Aircraft, they have an excellent website with lots of stuff pictured and listed. Also, they are good to do business with. If you buy used plastic make sure it is relatively new and not cracked or brittle.
I purchased a set of panels from them which were in excellent shape. I believe they were from Plane Plastics. In any case, I simply cleaned them well with rubbing alcahol and sprayed them with acrylic paint. They turned out great.....