Cut crystal prisms: large, clear, with few facets

I produce a high quality Animation called Spectrafocus created with large, bright, and clear Spectra. I need quality leaded glass crystal prisms that produce large spectra when properly placed in sunlight. Swarvoski makes a lot of them. Mainly interested in Octagons with 8 facets, clear 4 sided Pyramids, and Globes. Also want large optical glass prisms that are usually bars.