As you already have the stuff, you could try a builders merchants (I used some acrylic plastic I think it was for my Design Technology project a few years ago at school).
The problem is that normally you buy it in big sheets, sya 2m x 2m. They are around 50 quid.
Perhaps try
http://www.acrylic.co.uk/ - this will take you to a website called fascias and allows you to buy different types of plastic.
Oh, and Aryldite is good for sticking things - just make sure you never have to unstick it!!
