Jinkster,
Do you mean the type of thing that traffic officers wear rather than the waistcoats?
Try Greenham trading look in the Site construction section: Keep Safe EN 471 High Visibility Safety Clothing, they're fairly cheap as well ( They must be, they're an approved supplier to the cheapskates I work for) There are quite a few other places on the same lines. I think RS components do them as well. Try your local builders suppliers or work wear shop.
