I did a search for images of Tree Cake Stands. Orginially I was wanting to make the cake look like a real tree. However, after speaking to the client and showing her the stands made from tree "slices" she loves them! I have a friend who had a big tree fall in his yard last winter. He is going to cut the "slices" from the oak tree for use as stands. I'm doing 4 stands, 1-12" round that is 12-18" tall, 1-10" round that is 8-10" tall, 1-8" round that is 6" tall and 1-6" round that is about 4" tall. He's not charging me anything to cut them. He said, "I have to cut the tree up anyway, so whats a few more cuts."
Don't know where you live, but if there's a sawmill in your area they could cut them for you. Shouldn't cost too much. You could also look around for a downed tree and ask permission to cut them. I cut the one in my yard with a hand saw. YUCK. Too hard. I will post pictures when they are done! Thanks everyone!