I have an HQ Avante 18 (means the throat is 18") with a 12 foot frame. The frames for those are made especially and only for the HQs. I have quilted a number of king size quilts. As others said --- the larger the throat the less "passes" you have to make. Rolling it every time you do 5" gets very tiring. If you have the funds and the room, go for the larger throat space and the longer frame. Although I have a 12 foot frame and have done King size quilts, it would have been easier to have another foot of space on each side of the quilt --- it helps when loading the bobbins or rethreading.