These are all the domestic "larger than normal" sewing machines I know of:
Juki TL98 9"
Brother PQ 1500 9"
Babylock Quilters Dream Pro 9"
Pfaff Grand Hobby Quilter 9"
Janome 1600p 9"
Janome MC6500/6600 9"
Elna 7200/7300 9"
Viking/Husky Sapphire 10 or 11"
Janome Horizon 10 or 11"
Bernina 830? 10 or 11"
I believe Juki recently released or will soon release a longer than 9" throat/harp machine.
There are also stretched domestic machines. The Bailey Home Quilter is a stretched domestic machine. It comes in 13, 15 & I think, 17".
Wowquilts has a waiting list to stretch some of the above mentioned 9" straight stitch only machines into 18" machines. I haven't heard a single bad thing about the finished product other than the wait time to get it.
Looking at industrial machines is very confusing for me. Most seem to have the motor attached separately and they are so heavy; you wouldn't be moving them around your sewing room. They also run much, much faster than a domestic machine so they scare the crap out of me when they start up. And they take different needles and sometimes bobbins than domestic machines. If you have the space to setup one of the upholstery or sailcloth type industrial machines, you probably could use it to free motion quilt but having the extra space to leave the big honking thing is another story.