Most of the sources I've ever seen where European. I would make up my own caramel, either straight sugar water boiled til you got the color you wanted, boiled kayro syrup (since it appears brewer's caramel may be that) or a combination of both.
To me it's ridiculous to pay extra for something that is nothing more than any home cook/ candy maker makes all the time.
3 T sugar
Pinch cream of tartar
1/4 cup boiling water
"In a heavy saucepan over low heat, melt the sugar in the tablespoon of water. Increase the heat to medium-high, cover the pan, bring to a boil, and boil for 2 minutes. Add the cream of tartar and continue to boil, uncovered, until the sugar is almost black in color. Remove the pan from the heat. The sugar will continue cook and darken. Allow it to begin to cool. Using extreme care, add the boiling water (the sugar will boil up and may splatter). Stir to disolve, then let cool to room temperature.
You can also do it with honey. We did Brochet, a 5th century burnt honey mead this summer, just basically boiled honey and water for several hours until it was mahogany in color.
All the way to this....the taste was amazing