Big Bike Parts just came out with a full-size brake pedal for the Spyder. I installed it on my RT and am very pleased. It feels much more secure to have the pedal extend more than halfway across my foot. A bonus is that it seems like you don't have to press as hard to get strong braking when you need it. The best part is it was only $29.95. Here is a link.
http://www.bigbikeparts.com/templates/product.aspx?ProductGuid=41-179&GroupGuid=16
http://www.bigbikeparts.com/templates/product.aspx?ProductGuid=41-179&GroupGuid=16