Janome Magnolia.
Very lightweight but a good solid machine. Check with your local machine dealers. Sometimes people have traded up and you can get a used machine that's been totally checked out and sometimes even has a limited warranty. Also make sure that you use a reputable dealer with a good service reputation. Even the best machine is worth nothing if the place you bought it doesn't have good repair service.
And quilt lady is right too. The Jem is a great little machine.