Basically, when a domestic machine is advertised as a quilting machine, it has one or more of the following features:
Large harp area (area to the right of the needle), extended sewing base, comes with built in dual feed or walking foot, and has a setting or foot to achieve a 1/4" seam (which you will probably have to adjust anyway). These machines are not going to piece or quilt your quilt better than a machine without 'quilting' in the name, the features just make it easier. All these features can be used for regular sewing and many regular machines have some or all of these features.
I looked at the picture of the brother model you mention. Looks like a very small harp area. You are not going to easily get a big quilt in there to piece or quilt. I agree with the posters who mentioned going to a dealer and looking at what they have, or just getting an older straight stitch machine.