Some micro-distilleries are using C&H Yellow D (dark brown sugar), or raw sugar for making rum. Champagne yeast is generally used to produce a higher alcohol content and less off flavors. However, bread yeast can impart a fuller more complex flavor. This all depends on what you are using and how you distill. Used whiskey barrels are nice to use since they impart a slight oak flavor and are cheaper than new barrels. However, when using used whiskey barrels, be sure to rinse them thoroughly, or re-char them. I find this important to keep the rum from tasting more like whiskey and less like rum. Rogue dark rum is a good example of this. I'm not saying that it is a bad spirit, but it tastes more like a weak Jack Daniel's than it does a rum.
Just my two cents.
-Tyler