Pick a pantograph the same way you’d pick a font - by what ‘feels’ right, or speaks to you. Some suggestions to think about: Look for one that gives you the same “feeling” as your quilt top does. Or that shares similar or complementary shapes to the blocks or pieces or fabric prints (on the front or back) of your quilt. If you will be gifting it, look for one that reminds you of the future recipient.
Or, throw caution to the wind and pick one that completely contradicts my suggestions, and pair it with a bold thread color. There are no wrong choices, after all.