MQX midwest just had their annual show in Springfield IL (in October), which is only about 1 1/2 hours from St. Louis. I believe they are definitely returning next year but they usually don't make the announcement right away. They usually do midwest in the fall and east in the spring. There is no better place to take lessons on different aspects of longarming than at an MQX show. World class teachers, hands on with the longarms, lecture classes and loads of eye candy at the show. So during the year you can practice and research local sources but I highly recommend you consider MQX. Be aware most classes for hands on average well over $100 per class. You have to sign up for the classes as soon as they are announced. They fill up quickly. Here is a link to their website.
http://www.mqxshow.com/MQX/Home/index.cfm
You should probably sign up for email list so you will be notified. They also have a facebook page you can follow.
Good luck!!