NASMAH - National Association of Screen Make-up and Hairdressers.
On the links page there are a few organisations and companies which you can follow to their respective websites, the one I found most interesting was http://www.screenface.co.uk which sells regular make-up, stage make-up, sfx make-up and more.
The site is really easy to use, click on the catagory and select the product. The only downside is that it doesn't give much information about each product - for this you have to google it and find out from another site. A good site for this is: http://www.extrememakeup.co.uk they do sell their own products but also offer a detailed explanation of products, how to use them and what to use them for. Just search the product in the Search Box, and away you go.
This is the cheapest modelling wax available on screenface.co.uk that I could find. @ £3.95 plus £4.20 P&P it's the cheapest option. Not used it however and *might* order it when I get home.