I have 2 vikings and a brother. I like all of them. first is do you want to do free motion quilting on your quilts? Or just piece them and send them out to be quilted? do you want decorative stitches for crazy patch quilting or quilt first then assemble? I find I like my older machines for free motion quilting. Top loading bobbins I have to remove my slippery piece of vinyl before changing out a bobbin. You most likely will want a machine where the feed dogs drop, needle up/down position, one with a large size bobbin, so your not having to change bobbins all the time. Many older machines do a very good job of piecing and quilting and some you can get parts for even faster than some of the newer machines. I'd give anything for my 1962 Kenmore that I traded in. It was a work horse, but back then I wasn't into quilting, but it had beautiful straight stiches and went through just about anything. Hope you find something you will be happy with and good luck in your quilting.
Suzy