I think the whites will all look the same if you are more than 2 feet away from the quilt. There's nothing wrong with that. I bought an antique log cabin in December that has all white solid cotton as the lights. It's awesome.
You're obsessing over the fabric choice when there isn't much difference at all. The lights are all white, they add no color, just contrast--go with it! It's fine!!! You could be sewing, girl! GO GO GO!!