In either one of these styles...
http://http://www.hobbyhorseinc.com/shopping/siy/8112_janie.shtml
Ladies Classy Show Shirt in Ladies' Clothing at Schneider Saddlery
The second one isn't awful price wise, although cheaper would be better. The problem is that the colors are very limited.
My plan is too buy the shimmer sheets from hobby horse and crystals from walmart and make my own custom shirt. A red base is my color of choice. But If I have to I'll use black. I'd just really rather not. It seems like everybody wears black.