Hi Stephen! Well, the good news is that Goofy's Barnstormer is getting an exciting makeover and will become The Great Goofini when the expansion of Fantasyland is complete in 2013. The not-so-good news for you is that unfortunately Goofy's Barnstormer and the rest of Toontown will close in February to make way for this expansion.
You don't mention how old or how tall your son is, but a few other attractions are good for beginner coaster riders. I'm a ride wimp, but even I can handle
Big Thunder Mountain. If your son is 40 inches tall, he can ride this train coaster that, similar to the Barnstormer, has small dips and twists but no big drops. Test Track at Epcot is another great beginner thrill ride. The height requirement is also 40" and although the car goes really fast, there aren't any drops.
Hope you have a magical vacation in November! Come visit us again at the Moms Panel if we can help you plan your trip!