thank you ladies for all your comments. for the moment I have difficulty finding white on white fabric that I would like. Seems that 2 of the local QS do not carry much of white fabric.
I know that once the quilt is done and quilted it might not matter much which white I use.
I want to appliqué the next border, at least partially, before it is attached to the center panel, (10 or 11 inches wide ). It will make stitching so much easier.