I have a large Bernina now, but I did a couple large (90x100-ish) on my smaller Bernina. For me, the trick was having a machine table with the cut-out for the machine so the quilt was flat with the machine bed.
Good luck on your search! It's fun to get a new machine. And I agree about making sure it has a "needle down" feature. And I also really like my knee-lift feature.