ST,
I think your truck looks great, and you could certainly park it next to mine at any show. I didn't build mine to show either, it's truly driven every chance I get.
Here's a link to the GMC stick on center cap that I used on my steering wheel.
http://www.ebay.com/itm/4x-GMC-56mm-...6992ca&vxp=mtr
Here's are the same ones which are more expensive if you can't wait.
http://www.ebay.com/itm/GMC-WHEEL-CE...1e7f5f&vxp=mtr