What is the best variety of rice or preparation of rice to use in soup? I've made chicken rice soup several times in the past and I've always ran into an issue of the soup coming out too starchy/thick because of the rice. Or in the worst case scenario when I added too much rice, the soup ending up looking like rice porridge. 

Usually it isn't too much of a problem right after it's cooked. But after its been sitting in the fridge for a couple of hours, the issue becomes much more pronounced.

I recently had chicken rice soup at my work cafeteria and the rice grains seems fully in tact and the soup isn't overly starchy.

Is there a variety of rice that hold up better in soup where it doesn't disintegrate into a starchy mess? Or is there a preparation to help preserve the integrity of the rice grains?
I've found that the most consistent way is to use short grain rice that is prepared much like it is in Indian cuisine. I was taught to rinse it repeatedly until the standing rinse water runs clear. That seems to remove most of the starch that causes that sticky breakdown. 

Also, I've found that making rice soups in a slow cooker can be made less sticky by adding the rinsed rice after the other ingredients have settled in and become well heated. I've only dealt with this a couple times, so I definitely recommend experimenting if you prepare your soup in a slow cooker. Good luck!