I know a local distiller who uses mesquite barrels for their bourbon, which is a subspecies of acacia. Not sure if that would work for you. However, mesquite is much more expensive because it is a desert tree.
I have heard from a colleague who does high end millwork that there has been some issues with ethically sourcing acacia - they won't even sell it at a local wood workers shop now for fear of accidentally getting into a legal problem
Most Acacia for barrels comes from France and is actually Black Locust, the nominal name, and very invasive. It is not really a rare wood, only very hard and, as such, not easy to saw or mill. If you know what Locust bark looks like, you see it all over the eastern seaboard. It is very distinct and not uncommon. I see it all of the time in and around Philly.
They tend to grow like weeds though. They are really good at asexual repruction and send up shoots after a root system has developed. If you plant one Locust tree, in 10 years you will have quite a few growing around that initial one. The wood though is not pretty and is piss greenish yellow, and not something traditionally used for anything else then utility wood, like for fence posts on farms. Think of poplar, only less appealing in color. It is extremely hard, resistant to rot, and burns so hot it is not good to use for a firewood unless you have a stove designed for coal. It will re-temper a wood burning stoves if you use it for heating wood. It will also dull blades on saw on the same level as Teak.
France imported a decent amount of Black Locust in the 1800s and 1900s before its invasiveness was apparent and they are dealing with the issues. This is why I think Acacia was initially utilized in wine barrels, to take care of the issue.
It also produces an abundance of tyloses, like oak, which are hardened mineral deposits in the xylem and phloem of the heartwood that clogs up the "veins" preventing leakage. Other hardwoods, like Maple, do not produce nearly as much and is why those woods are not used for barrels. Without tyloses, the barrels will leak. I can see mesquite being more rare due to the growing environment, but Acacia is now part of the French environment now and needs to be cleared.