I also feed the Purina Show Rabbit and have had great results with it. Is see you feed that at the Professional. You need to stick with JUST the Show for the chins.
Chinchillas do have a breed standard and there are are chinchilla shows. They are usually in the winter because it is much safer to travel with them then. There are two major organizations that host sanctioned shows: MCBA and EMPRESS.
Standards are still based on pelting guidelines. The shoulders should be as wide as the hips. The fur should stand up straight all over the body with no lay down around the hips, no swirls, parts, ect. (Although you will see parts in the fur while they are out of prime) You only want to show a chinchilla when it is in full prime, and the best is its first prime at around months.
There are all sorts of color rules depending on the color of your chinchilla but all should have a blueish tinge under light. Yellow or red is bad.
Here is an article I wrote awhile back that goes over the basics.
http://www.lowcountrychinchillas.com/0804pair2.shtmlYou might also find this one helpful
http://www.lowcountrychinchillas.com/fur.shtml