I found this tutorial a while ago that I used when I wanted to make the shield. It's a Photoshop tutorial but the workflow method can be applied to creating your texture base for the shield itself. http://abduzeedo.com/captain-america-shield-photoshop
Thanks for the feedback :) Right now the shield is on pause as I look to progress the character but thanks for the texture advice. And yes specular maps are allowed and i plan to use some of the effects from the photoshop tutorial to help with the specular :)