http://www.wholesaletoolwarehouse.com/mechanical-engineering/rules/mt69-steel-rule http://www.directplasticsonline.co.uk/Nylon6Sheet/Natural/16mm/
http://www.nutandboltman.com/4-x1-bzp-recessed-csk-self-tap-screws-23950-p.asp
Make yourself a few... For almost half the price of a heatsink one...