Those are all great suggestions. My Janome dealer is also the largest fabric store in the county. It was on sale and when I sent to the store to check it out I told the sales lady that I was a quilter, that I did not make clothes anymore and my concern was being able to quilt on the machine. So she didn't waste my time showing me the embroidery/sewing machine. But she did say that I wanted a machine above what I have now so that I can grow. And she explained why I wanted the bells and whistles Onebyone talks about and how they become so necessary while quilting. (I don't care about the knee lift - never got used to it, but know a lot of people love it.)
Also the suggestion to go to a major show with all the different vendors is one place is also good, but my create a long delay and all the sales are going on now.
Just don't feel pressured to buy anything while checking them out.
One additional item I would suggest you get, if possible, is the sewing table so that your machine sets into it. My Janome came with it. My old Singer is in a cabinet so was used to having the flat surface. Two of my machines have the acrylic tables and those just aren't the same. I got the SewEz table for my Husqvarna, you order it based on the machine you have. I also got the piece to put in when the machine is out of it to close the hole.
Have fun shopping. Let us know what you decide.