You could use the soft brass wire offered by Detail Associates if you want to do it as rods. I think that Grandt Line makes the band tighteners (turnbuckles) in styrene.
If you want to use the band idea, try cutting strips of good quality writing paper using a new blade in your X-acto. My Dad used this technique on a water tower that he built almost 50 years ago, from an article in Model Railroader. He brush painted them with Floquil before applying them to the tank. The tank still looks good after all those years, and I'll be using it in the first town on the new extension, when/if I ever get the second level of my layout built.
Wayne