There are a tonne of flavor houses. Givaudan is one that I have used previously, for example. Orange is not "orange" from one company to another (they'll taste different). Check out Moonshine University in Louisville, or whatever their bottling line is called,. It might be worth hiring out your first couple batches while you can use their flavor scientist. I've never used Dehner but he apparently knows what he is doing as well.
To the OP - make it from scratch, buy extracts, blend the two together - doesn't matter in the end. Do what is right for your brand. There's nothing immoral