It's a smart idea for you to do them yourself. You'll get a new experience and save some money.
There are two kinds of diamonds plate, steel and aluminum. The only differance is wieght and flexablity.
If you get the aluminum it will be cheaper, easier to cut and bend. The steel ones you better have some seriuos power tools.
I bought mine from this place and got ripped. Stay away from them they suck all around.http://www.usspeedonline.com/page/U/PROD/L5-TO11