Are you planning to try out different machines before purchasing? It's a really good idea to do that. Also, have you considered buying a used machine from a dealership? You can get a lot more bang-for-your-buck that way, as there are always customers who trade in a slightly used model for the newest model.
I did a search on Amazon for sewing machines in your price range and sorted the results in order of average customer review. These two were the two top listed:
http://www.amazon.com/Janome-DC2012-...dp/B007JBQYQM/
http://www.amazon.com/Janome-DC2013-...dp/B00B0FDITE/
I couldn't find the Janome 2030 on Amazon.
Both of these have the smaller throat size. For $500 I don't think you are going to find a new machine with a large throat size that also has a variety of stitches. Also in that price range you will not find a built-in accufeed. I have an older Bernina and do not miss having a built-in accufeed. You will probably want a walking foot, though, for quilting.