Tin Lizzie does make the Queen Quilter and they make the Viking you looked at if it was the 18.8 Mega Quilter.
I'm confused by the machines you listed in your price range. You have one of my dream machinse--the A1 Elite, listed with the home systems whereas it is more like the professional Nolting, Gammil & APQS systems.
The low end of the midarm (home quilting systems) would be the Bailey Home Quilter, Voyager or a stretched 9" machine by wowquilts--the same people who make the WOW quilter you mentioned will stretch the 9" straight stitch only domestic machines--Juki TL98, Brother 1500, Janome mc1600, etc.
The next step would be the Tin Lizzies, Nolting FunQuilter, Pennywinkle Valley Ranch Sunshine 16, KenQuilt, Homesteader, etc.
Then you move up into the big guys which is where I would place the HandiQuilter, Crystal Quilter, Innova, Nolting Pro and others.
Also, Nolting, KenQuilt, HandiQuilter, Pennywinkle and others make several different machines at different price points.
The only real way to know the differences and find out which one is "the one" is to research, research, research and try to get your hands on as many different ones as you can. If you can get to a quilt show that will have several in one place--that is your best bet.
I started with a B-Line Studio frame and an Elna 7200 domestic 9" sewing machine (very similar to the Janome MC6500p) I was very happy with that system for 5 years and would still be using it if I hadn't stumbled over a Voyager 17 SLR on a Pro-Flex frame for a dirt cheap price. If I had aspirations of running a quilting business, though, I would be looking at the professional systems which are a whole 'nuther kettle of fish.