My goodness, you are so lucky to attend 10 classes a year. I get to take about three, but I love taking my Janome 3160 to class. Is 11 lbs. and has the thread cutter feature, which is great of piecing,....that is all I do in these classes is piecing, so it moves along quickly with the cutter feature. It has a lot of other features as well, check that one out.
If you don't want the cutter, then opt for the Janome Jem. Janomes have a metal frame so it will stand up to a lot of use. Check dealers for a used 3160 is the price of a new one is too high.