take a look at these:
http://www.haberfieldpublicschool.com/information/news/haberfield-children-awarded-unsw-medals.shtml
http://www.123rf.com/stock-photo/certificate.html
http://www.clker.com/search/certificates+medal/1
http://www.twinkl.co.uk/resource/t-m-011-editable-reward-medals
http://www.twinkl.co.uk/resource/t-c-029-editable-sports-day-award-certificates