http://www.generations-quilt-pattern...e-reviews.html This has some reviews on it that may help.
I bought, 7 years ago, an Elna 7200 for £900/$1400 and although it has been, and still is a fabulous machine, I would never buy a modern one again. I prefer the stability, durability and dependability of the older machines. Although your wife's first quilt was made from Jeans/Denim I doubt that she will be making heaps more so what you need to do is to go for a good all-rounder machine for quilting.
All makes of machines up to the late 70's were manufactured to a very high standard, were made from metal with a minimum of plastic bits n pieces.
I did a quick search for you and found this company "Allbrands.com" and spotted what looks like a fantastic buy, this Refurbished commercial grade Singer
http://www.allbrands.com/categories/...rade-freearm-s for only $299!!!!!!!!!!! When you read the spec. it looks as tho' it would sew through anything especially with that extra powered motor.
This is another link for the same machine, which gives you more information and $10 less:
http://www.sewingmachinesplus.com/singer-590fs.php
Do let us know what you decide on.