You can get mason jars anywhere you look, direct from ULINE or at large stores like Walmart, etc. If you are looking for more pastry style containers for your layered desserts there is www.bakedeco.com
Thank you Fablesable for your prompt reply! The ones at bakedeco.com are just what we are looking for. I knew they carried those type of containers, but was not aware that they also have lids for them. Thank you for pointing me back to this site !