Dude, a local headshop should have great bowls of varying sizes and shapes, along with stems, for only a few bucks a piece. They're nice to switch out to bigger ones for company or clean ones for pretending you've never used it. I always keep a clean cone and a party bowl floating around my collection. Besides, trumpet mouthpieces are too shallow to use as oneys, and if you're building a bong you might as well spring the two bucks for a nice bowl. On the other hand, I worship my trumpet as God. Arturo Sandoval is Jesus.