@Callie Beller Diesel@neilestrick thanks for all the info! I'm actually asking on behalf of my mentor who has made 4 ft large crystalline glazed wall plates (fine art) and dreams of taking it further. Trying to help him out. He's helped me so much! So to answer your question, I know he would be willing to rent an entire kiln.
I also know that the kiln would need to get up to at least 2300° and be able to hold/soak for the crystalline process.