I'm sure you'll find some fake pics on ebay. Super-fakes, this-style-doesn't exist fake, cheap fake etc. However you decide to approach the issue is up to you (love amanda's ideas). I'm sure you'll be fine!
I did my informative speech on Bulimia Nervosa. I think it's interesting to pick a topic that a lot of college students are affected by, and can relate to. I had girls come up to me after class and talk about their problems with it, I was very happy to inform people of something that is a very real disease- a lot of people don't even know the differences between bulimia and anorexia.
My point is, pick a topic you feel passionate about, if it's designers- go for it. You're always going to give a better speech about a topic you love.