I think going to the ASG Expo is a good idea. You can check out all of the differant machines to find the perfect one for you.
In the meantime you might want to go to the machine sites:
Husqvarna Viking, Bernina, Janome, etc. You can find info there on their different models and the features they have. It's nice to be able to do some comparisons before you talk to a salesperson.
Good luck and fun picking out a new one.