Contact cajon makers directly to find cajons made in Austria. Unfortunately most big online retailers and many music stores only carry imported brands. Buying a locally made cajon cyles your income back through your local economy. Below are links to 2 cajon makers in Austria:
Minimize the carbon footprint of your cajon purchase - buy a locally made cajon directly from the cajon builder. Most imported cajons are shipped around the planet in big cargo ships. A locally made cajon helps your local economy and demonstrates that you are thinking about and helping local craftsmen.
Listed above are links to the cajon drum builders in Austria as retrieved by Internet searches in March 2018. I am sure there are many others not listed. Please send me updates and correction if you have additional information. Thanks.