I have a JUKI TL98QE and a Babylock Jane 9" Throat/harp space and I can quilt any size quilt I want to on them. An 18" would be wonderful to quilt on. I don't have room for a frame or an 18" machine. I will just be happy with what I have.
If you put the 18" on a frame, youu could get another for piecing, used or more simple machine.