here's the queen quilter 18 that has gotten some good reviews in the market.
http://www.sewingmachinesplus.com/tinlizzie-qqsd.php
just remember you'll still have to deal with the weight of moving a large quilt around and all the drag that comes with it.
i strongly suggest you give this a test run with your "typical" large quilt and see if you have better results before you purchase.