For quilting you'll want something that doesn't get jammed up with heavy bulky fabrics. I've used this Brother for quilting before (my sister owns one) and it's a nice machine for the price:
http://www.top-sewing-machines.com/review/brother-hc1850/2If you can afford it, this Janome has been one of my favorite all-around machines and stitches as nicely as some of the commercial machines I've used:
http://www.top-sewing-machines.com/review/janome-dc2012/9If you buy from a store they will sometimes teach you how to use the machine, but if you buy online (at least through Amazon) they're going to be much more friendly about returns. As for the machine itself, there are a lot of great quilting machines out there - these are just two of my favorites for under $500. Hope this helps!
